Extend GCMole with poor man's data flow analysis to catch dead raw pointer vars.

src/arm/stub-cache-arm.cc

 // Copyright 2011 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 3510 matching lines @@
 
     if (CpuFeatures::IsSupported(VFP3)) {
       CpuFeatures::Scope scope(VFP3);
       __ vmov(s0, value);
       __ vcvt_f64_s32(d0, s0);
       __ sub(r3, r0, Operand(kHeapObjectTag));
       __ vstr(d0, r3, HeapNumber::kValueOffset);
       __ Ret();
     } else {
       WriteInt32ToHeapNumberStub stub(value, r0, r3);
-      __ TailCallStub(&stub);
+      MaybeObject* stub_code = masm()->TryTailCallStub(&stub);
+      if (stub_code->IsFailure()) return stub_code;
     }
   } else if (array_type == kExternalUnsignedIntArray) {
     // The test is different for unsigned int values. Since we need
     // the value to be in the range of a positive smi, we can't
     // handle either of the top two bits being set in the value.
     if (CpuFeatures::IsSupported(VFP3)) {
       CpuFeatures::Scope scope(VFP3);
       Label box_int, done;
       __ tst(value, Operand(0xC0000000));
       __ b(ne, &box_int);
@@ skipping 511 matching lines @@
 
   return GetCode(flags);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM