[6/9,LVU] Allow final_start_function to skip initial insns

diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index 28c4e0e..51584f5 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -3936,7 +3936,7 @@  aarch64_output_mi_thunk (FILE *file, tree thunk ATTRIBUTE_UNUSED,
 
   insn = get_insns ();
   shorten_branches (insn);
-  final_start_function (insn, file, 1);
+  final_start_function (&insn, file, 1);
   final (insn, file, 1);
   final_end_function ();
 
diff --git a/gcc/config/alpha/alpha.c b/gcc/config/alpha/alpha.c
index e13c5f9..c158f7a 100644
--- a/gcc/config/alpha/alpha.c
+++ b/gcc/config/alpha/alpha.c
@@ -8461,7 +8461,7 @@  alpha_output_mi_thunk_osf (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
      assemble_start_function and assemble_end_function.  */
   insn = get_insns ();
   shorten_branches (insn);
-  final_start_function (insn, file, 1);
+  final_start_function (&insn, file, 1);
   final (insn, file, 1);
   final_end_function ();
 }
diff --git a/gcc/config/arm/arm.c b/gcc/config/arm/arm.c
index fa3e2fa..71a0d2d 100644
--- a/gcc/config/arm/arm.c
+++ b/gcc/config/arm/arm.c
@@ -26357,7 +26357,8 @@  arm_thumb1_mi_thunk (FILE *file, tree, HOST_WIDE_INT delta,
   if (mi_delta < 0)
     mi_delta = - mi_delta;
 
-  final_start_function (emit_barrier (), file, 1);
+  rtx_insn *first = emit_barrier ();
+  final_start_function (&first, file, 1);
 
   if (TARGET_THUMB1)
     {
@@ -26534,7 +26535,7 @@  arm32_output_mi_thunk (FILE *file, tree, HOST_WIDE_INT delta,
 
   insn = get_insns ();
   shorten_branches (insn);
-  final_start_function (insn, file, 1);
+  final_start_function (&insn, file, 1);
   final (insn, file, 1);
   final_end_function ();
 
diff --git a/gcc/config/cris/cris.c b/gcc/config/cris/cris.c
index b57881a..376c1eb 100644
--- a/gcc/config/cris/cris.c
+++ b/gcc/config/cris/cris.c
@@ -2744,7 +2744,8 @@  cris_asm_output_mi_thunk (FILE *stream,
 			  tree funcdecl)
 {
   /* Make sure unwind info is emitted for the thunk if needed.  */
-  final_start_function (emit_barrier (), stream, 1);
+  rtx_insn *first = emit_barrier ();
+  final_start_function (&first, stream, 1);
 
   if (delta > 0)
     fprintf (stream, "\tadd%s " HOST_WIDE_INT_PRINT_DEC ",$%s\n",
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 1d88e4f..86320a7 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -12492,8 +12492,9 @@  ix86_code_end (void)
 	 emitting it directly; tell them we're a thunk, if they care.  */
       cfun->is_thunk = true;
       first_function_block_is_cold = false;
+      rtx_insn *first = emit_barrier ();
       /* Make sure unwind info is emitted for the thunk if needed.  */
-      final_start_function (emit_barrier (), asm_out_file, 1);
+      final_start_function (&first, asm_out_file, 1);
 
       /* Pad stack IP move with 4 instructions (two NOPs count
 	 as one instruction).  */
@@ -42615,7 +42616,7 @@  x86_output_mi_thunk (FILE *file, tree, HOST_WIDE_INT delta,
      Note that use_thunk calls assemble_start_function et al.  */
   insn = get_insns ();
   shorten_branches (insn);
-  final_start_function (insn, file, 1);
+  final_start_function (&insn, file, 1);
   final (insn, file, 1);
   final_end_function ();
 }
diff --git a/gcc/config/ia64/ia64.c b/gcc/config/ia64/ia64.c
index 79c323f..2a05293 100644
--- a/gcc/config/ia64/ia64.c
+++ b/gcc/config/ia64/ia64.c
@@ -10944,7 +10944,7 @@  ia64_output_mi_thunk (FILE *file, tree thunk ATTRIBUTE_UNUSED,
   emit_all_insn_group_barriers (NULL);
   insn = get_insns ();
   shorten_branches (insn);
-  final_start_function (insn, file, 1);
+  final_start_function (&insn, file, 1);
   final (insn, file, 1);
   final_end_function ();
 
diff --git a/gcc/config/m68k/m68k.c b/gcc/config/m68k/m68k.c
index 8972665..3b656c7 100644
--- a/gcc/config/m68k/m68k.c
+++ b/gcc/config/m68k/m68k.c
@@ -5131,7 +5131,7 @@  m68k_output_mi_thunk (FILE *file, tree thunk ATTRIBUTE_UNUSED,
   /* Run just enough of rest_of_compilation.  */
   insn = get_insns ();
   split_all_insns_noflow ();
-  final_start_function (insn, file, 1);
+  final_start_function (&insn, file, 1);
   final (insn, file, 1);
   final_end_function ();
 
diff --git a/gcc/config/microblaze/microblaze.c b/gcc/config/microblaze/microblaze.c
index 2cdd240..9f862292 100644
--- a/gcc/config/microblaze/microblaze.c
+++ b/gcc/config/microblaze/microblaze.c
@@ -3233,7 +3233,7 @@  microblaze_asm_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
      "borrowed" from rs6000.c.  */
   insn = get_insns ();
   shorten_branches (insn);
-  final_start_function (insn, file, 1);
+  final_start_function (&insn, file, 1);
   final (insn, file, 1);
   final_end_function ();
 
diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
index d2737a6..7dcc835 100644
--- a/gcc/config/mips/mips.c
+++ b/gcc/config/mips/mips.c
@@ -19353,7 +19353,7 @@  mips_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
   split_all_insns_noflow ();
   mips16_lay_out_constants (true);
   shorten_branches (insn);
-  final_start_function (insn, file, 1);
+  final_start_function (&insn, file, 1);
   final (insn, file, 1);
   final_end_function ();
 
diff --git a/gcc/config/nds32/nds32.c b/gcc/config/nds32/nds32.c
index 14310de..478824f 100644
--- a/gcc/config/nds32/nds32.c
+++ b/gcc/config/nds32/nds32.c
@@ -1635,7 +1635,8 @@  nds32_asm_output_mi_thunk (FILE *file, tree thunk ATTRIBUTE_UNUSED,
   int this_regno;
 
   /* Make sure unwind info is emitted for the thunk if needed.  */
-  final_start_function (emit_barrier (), file, 1);
+  rtx_insn *first = emit_barrier ();
+  final_start_function (&first, file, 1);
 
   this_regno = (aggregate_value_p (TREE_TYPE (TREE_TYPE (function)), function)
 		? 1
diff --git a/gcc/config/nios2/nios2.c b/gcc/config/nios2/nios2.c
index 884b1dc..89600ee 100644
--- a/gcc/config/nios2/nios2.c
+++ b/gcc/config/nios2/nios2.c
@@ -4060,7 +4060,7 @@  nios2_asm_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
      assemble_start_function and assemble_end_function.  */
   insn = get_insns ();
   shorten_branches (insn);
-  final_start_function (insn, file, 1);
+  final_start_function (&insn, file, 1);
   final (insn, file, 1);
   final_end_function ();
 
diff --git a/gcc/config/pa/pa.c b/gcc/config/pa/pa.c
index 52f76cf..fd28213 100644
--- a/gcc/config/pa/pa.c
+++ b/gcc/config/pa/pa.c
@@ -8379,7 +8379,8 @@  pa_asm_output_mi_thunk (FILE *file, tree thunk_fndecl, HOST_WIDE_INT delta,
   xoperands[1] = XEXP (DECL_RTL (thunk_fndecl), 0);
   xoperands[2] = GEN_INT (delta);
 
-  final_start_function (emit_barrier (), file, 1);
+  rtx_insn *first = emit_barrier ();
+  final_start_function (&first, file, 1);
 
   /* Output the thunk.  We know that the function is in the same
      translation unit (i.e., the same space) as the thunk, and that
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index f9aa13b..298f07a 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -29292,7 +29292,7 @@  rs6000_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
      assemble_start_function and assemble_end_function.  */
   insn = get_insns ();
   shorten_branches (insn);
-  final_start_function (insn, file, 1);
+  final_start_function (&insn, file, 1);
   final (insn, file, 1);
   final_end_function ();
 
@@ -37758,7 +37758,8 @@  rs6000_code_end (void)
   init_function_start (decl);
   first_function_block_is_cold = false;
   /* Make sure unwind info is emitted for the thunk if needed.  */
-  final_start_function (emit_barrier (), asm_out_file, 1);
+  rtx_insn *first = emit_barrier ();
+  final_start_function (&first, asm_out_file, 1);
 
   fputs ("\tblr\n", asm_out_file);
 
diff --git a/gcc/config/s390/s390.c b/gcc/config/s390/s390.c
index deced95..ce98673 100644
--- a/gcc/config/s390/s390.c
+++ b/gcc/config/s390/s390.c
@@ -12872,7 +12872,8 @@  s390_output_mi_thunk (FILE *file, tree thunk ATTRIBUTE_UNUSED,
   int nonlocal = 0;
 
   /* Make sure unwind info is emitted for the thunk if needed.  */
-  final_start_function (emit_barrier (), file, 1);
+  rtx_insn *first = emit_barrier ();
+  final_start_function (&first, file, 1);
 
   /* Operand 0 is the target function.  */
   op[0] = XEXP (DECL_RTL (function), 0);
diff --git a/gcc/config/sh/sh.c b/gcc/config/sh/sh.c
index c31776f..875d931 100644
--- a/gcc/config/sh/sh.c
+++ b/gcc/config/sh/sh.c
@@ -10891,7 +10891,7 @@  sh_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
 
   sh_reorg ();
   shorten_branches (insns);
-  final_start_function (insns, file, 1);
+  final_start_function (&insns, file, 1);
   final (insns, file, 1);
   final_end_function ();
 
diff --git a/gcc/config/sparc/sparc.c b/gcc/config/sparc/sparc.c
index d494ecf2..5d92080 100644
--- a/gcc/config/sparc/sparc.c
+++ b/gcc/config/sparc/sparc.c
@@ -12074,7 +12074,7 @@  sparc_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
      assemble_start_function and assemble_end_function.  */
   insn = get_insns ();
   shorten_branches (insn);
-  final_start_function (insn, file, 1);
+  final_start_function (&insn, file, 1);
   final (insn, file, 1);
   final_end_function ();
 
diff --git a/gcc/config/spu/spu.c b/gcc/config/spu/spu.c
index b6d03d7..e005077 100644
--- a/gcc/config/spu/spu.c
+++ b/gcc/config/spu/spu.c
@@ -7020,7 +7020,8 @@  spu_output_mi_thunk (FILE *file, tree thunk ATTRIBUTE_UNUSED,
   rtx op[8];
 
   /* Make sure unwind info is emitted for the thunk if needed.  */
-  final_start_function (emit_barrier (), file, 1);
+  rtx_insn *insn = emit_barrier ();
+  final_start_function (&insn, file, 1);
 
   /* Operand 0 is the target function.  */
   op[0] = XEXP (DECL_RTL (function), 0);
diff --git a/gcc/config/tilegx/tilegx.c b/gcc/config/tilegx/tilegx.c
index 81559ac..ac4a5ff 100644
--- a/gcc/config/tilegx/tilegx.c
+++ b/gcc/config/tilegx/tilegx.c
@@ -4998,7 +4998,7 @@  tilegx_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
    */
   insn = get_insns ();
   shorten_branches (insn);
-  final_start_function (insn, file, 1);
+  final_start_function (&insn, file, 1);
   final (insn, file, 1);
   final_end_function ();
 
diff --git a/gcc/config/tilepro/tilepro.c b/gcc/config/tilepro/tilepro.c
index f03f067..34b68b8 100644
--- a/gcc/config/tilepro/tilepro.c
+++ b/gcc/config/tilepro/tilepro.c
@@ -4421,7 +4421,7 @@  tilepro_asm_output_mi_thunk (FILE *file, tree thunk_fndecl ATTRIBUTE_UNUSED,
    */
   insn = get_insns ();
   shorten_branches (insn);
-  final_start_function (insn, file, 1);
+  final_start_function (&insn, file, 1);
   final (insn, file, 1);
   final_end_function ();
 
diff --git a/gcc/final.c b/gcc/final.c
index 401cfb6..15a301b 100644
--- a/gcc/final.c
+++ b/gcc/final.c
@@ -1770,9 +1770,11 @@  get_some_local_dynamic_name ()
      test and compare insns.  */
 
 void
-final_start_function (rtx_insn *first, FILE *file,
+final_start_function (rtx_insn **firstp, FILE *file,
 		      int optimize_p ATTRIBUTE_UNUSED)
 {
+  rtx_insn *first = *firstp;
+
   block_depth = 0;
 
   this_is_asm_operands = 0;
@@ -4544,8 +4546,9 @@  rest_of_handle_final (void)
     variable_tracking_main ();
 
   assemble_start_function (current_function_decl, fnname);
-  final_start_function (get_insns (), asm_out_file, optimize);
-  final (get_insns (), asm_out_file, optimize);
+  rtx_insn *first = get_insns ();
+  final_start_function (&first, asm_out_file, optimize);
+  final (first, asm_out_file, optimize);
   if (flag_ipa_ra
       && !lookup_attribute ("noipa", DECL_ATTRIBUTES (current_function_decl)))
     collect_fn_hard_reg_usage ();
diff --git a/gcc/output.h b/gcc/output.h
index 7a93fa8..278315f 100644
--- a/gcc/output.h
+++ b/gcc/output.h
@@ -59,7 +59,7 @@  const char *get_some_local_dynamic_name ();
    for the new function.  The label for the function and associated
    assembler pseudo-ops have already been output in
    `assemble_start_function'.  */
-extern void final_start_function (rtx_insn *, FILE *, int);
+extern void final_start_function (rtx_insn **, FILE *, int);
 
 /* Output assembler code for the end of a function.
    For clarity, args are same as those of `final_start_function'