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

src/arm/macro-assembler-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 1739 matching lines @@
   Jump(stub->GetCode(), RelocInfo::CODE_TARGET, cond);
 }
 
 
 MaybeObject* MacroAssembler::TryTailCallStub(CodeStub* stub, Condition cond) {
   ASSERT(allow_stub_calls());  // Stub calls are not allowed in some stubs.
   Object* result;
   { MaybeObject* maybe_result = stub->TryGetCode();
     if (!maybe_result->ToObject(&result)) return maybe_result;
   }
-  Jump(stub->GetCode(), RelocInfo::CODE_TARGET, cond);
+  Jump(Handle<Code>(Code::cast(result)), RelocInfo::CODE_TARGET, cond);
   return result;
 }
 
 
 static int AddressOffset(ExternalReference ref0, ExternalReference ref1) {
   return ref0.address() - ref1.address();
 }
 
 
 MaybeObject* MacroAssembler::TryCallApiFunctionAndReturn(
@@ skipping 1292 matching lines @@
 void CodePatcher::EmitCondition(Condition cond) {
   Instr instr = Assembler::instr_at(masm_.pc_);
   instr = (instr & ~kCondMask) | cond;
   masm_.emit(instr);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM