Add a trap_on_abort flag

src/x64/macro-assembler-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 506 matching lines @@
   const char* msg = GetBailoutReason(reason);
   intptr_t p1 = reinterpret_cast<intptr_t>(msg);
   intptr_t p0 = (p1 & ~kSmiTagMask) + kSmiTag;
   // Note: p0 might not be a valid Smi _value_, but it has a valid Smi tag.
   ASSERT(reinterpret_cast<Object*>(p0)->IsSmi());
 #ifdef DEBUG
   if (msg != NULL) {
     RecordComment("Abort message: ");
     RecordComment(msg);
   }
+
+  if (FLAG_trap_on_abort) {
+    int3();
+    return;
+  }
 #endif
+
   push(rax);
   movq(kScratchRegister, p0, RelocInfo::NONE64);
   push(kScratchRegister);
   movq(kScratchRegister,
        reinterpret_cast<intptr_t>(Smi::FromInt(static_cast<int>(p1 - p0))),
        RelocInfo::NONE64);
   push(kScratchRegister);
 
   if (!has_frame_) {
     // We don't actually want to generate a pile of code for this, so just
@@ skipping 4156 matching lines @@
   j(greater, &no_memento_available);
   CompareRoot(MemOperand(scratch_reg, -AllocationMemento::kSize),
               Heap::kAllocationMementoMapRootIndex);
   bind(&no_memento_available);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64