Regression fix: HForceRepresentation shouldn't be an idef.

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 2124 matching lines @@
 
   double nan_double = FixedDoubleArray::hole_nan_as_double();
   HValue* hole = IsFastSmiOrObjectElementsKind(elements_kind)
       ? Add<HConstant>(factory->the_hole_value())
       : Add<HConstant>(nan_double);
 
   // Special loop unfolding case
   static const int kLoopUnfoldLimit = 8;
   STATIC_ASSERT(JSArray::kPreallocatedArrayElements <= kLoopUnfoldLimit);
   int initial_capacity = -1;
-  if (from->ActualValue()->IsConstant() && to->ActualValue()->IsConstant()) {
-    HConstant* constant_from = HConstant::cast(from->ActualValue());
-    HConstant* constant_to = HConstant::cast(to->ActualValue());
+  if (from->IsInteger32Constant() && to->IsInteger32Constant()) {
+    int constant_from = from->GetInteger32Constant();
+    int constant_to = to->GetInteger32Constant();
 
-    if (constant_from->HasInteger32Value() &&
-        constant_from->Integer32Value() == 0 &&
-        constant_to->HasInteger32Value() &&
-        constant_to->Integer32Value() <= kLoopUnfoldLimit) {
-      initial_capacity = constant_to->Integer32Value();
+    if (constant_from == 0 && constant_to <= kLoopUnfoldLimit) {
+      initial_capacity = constant_to;
     }
   }
 
   // Since we're about to store a hole value, the store instruction below must
   // assume an elements kind that supports heap object values.
   if (IsFastSmiOrObjectElementsKind(elements_kind)) {
     elements_kind = FAST_HOLEY_ELEMENTS;
   }
 
   if (initial_capacity >= 0) {
@@ skipping 8168 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal