Fixed crashes exposed though fuzzing.

src/hydrogen.cc

 // Copyright 2013 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 9697 matching lines @@
 
 void HOptimizedGraphBuilder::GenerateOneByteSeqStringSetChar(
     CallRuntime* call) {
   ASSERT(call->arguments()->length() == 3);
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
   CHECK_ALIVE(VisitForValue(call->arguments()->at(1)));
   CHECK_ALIVE(VisitForValue(call->arguments()->at(2)));
   HValue* value = Pop();
   HValue* index = Pop();
   HValue* string = Pop();
-  HSeqStringSetChar* result = New<HSeqStringSetChar>(
-      String::ONE_BYTE_ENCODING, string, index, value);
-  return ast_context()->ReturnInstruction(result, call->id());
+  Add<HSeqStringSetChar>(String::ONE_BYTE_ENCODING, string,
+                         index, value);
+  Add<HSimulate>(call->id(), FIXED_SIMULATE);
+  return ast_context()->ReturnValue(graph()->GetConstantUndefined());
 }
 
 
 void HOptimizedGraphBuilder::GenerateTwoByteSeqStringSetChar(
     CallRuntime* call) {
   ASSERT(call->arguments()->length() == 3);
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
   CHECK_ALIVE(VisitForValue(call->arguments()->at(1)));
   CHECK_ALIVE(VisitForValue(call->arguments()->at(2)));
   HValue* value = Pop();
   HValue* index = Pop();
   HValue* string = Pop();
-  HSeqStringSetChar* result = New<HSeqStringSetChar>(
-      String::TWO_BYTE_ENCODING, string, index, value);
-  return ast_context()->ReturnInstruction(result, call->id());
+  Add<HSeqStringSetChar>(String::TWO_BYTE_ENCODING, string,
+                         index, value);
+  Add<HSimulate>(call->id(), FIXED_SIMULATE);
+  return ast_context()->ReturnValue(graph()->GetConstantUndefined());
 }
 
 
 void HOptimizedGraphBuilder::GenerateSetValueOf(CallRuntime* call) {
   ASSERT(call->arguments()->length() == 2);
   CHECK_ALIVE(VisitForValue(call->arguments()->at(0)));
   CHECK_ALIVE(VisitForValue(call->arguments()->at(1)));
   HValue* value = Pop();
   HValue* object = Pop();
   // Check if object is a not a smi.
@@ skipping 877 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal