Ensures that GDB prints stacktraces correctly for x64 builds when debugging t...

src/full-codegen.cc

Index: src/full-codegen.cc
===================================================================
--- src/full-codegen.cc	(revision 6445)
+++ src/full-codegen.cc	(working copy)
@@ -288,7 +288,10 @@
   MacroAssembler masm(NULL, kInitialBufferSize);
 #ifdef ENABLE_GDB_JIT_INTERFACE
   masm.positions_recorder()->StartGDBJITLineInfoRecording();
+#ifdef V8_TARGET_ARCH_X64
+  UnwindInfoInterface dummy;
 #endif
+#endif
 
   FullCodeGenerator cgen(&masm);
   cgen.Generate(info);
@@ -300,6 +303,10 @@
 
   Code::Flags flags = Code::ComputeFlags(Code::FUNCTION, NOT_IN_LOOP);
   Handle<Code> code = CodeGenerator::MakeCodeEpilogue(&masm, flags, info);
+
+  SET_UNWIND_INFO_START_ADDRESS(reinterpret_cast<uintptr_t>
+                                (code->instruction_start()));
+
   code->set_optimizable(info->IsOptimizable());
   cgen.PopulateDeoptimizationData(code);
   code->set_has_deoptimization_support(info->HasDeoptimizationSupport());