Fix context register allocation in LTransitionElementsKind.

src/ia32/lithium-codegen-ia32.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 4827 matching lines @@
   if (is_simple_map_transition) {
     Register new_map_reg = ToRegister(instr->new_map_temp());
     __ mov(FieldOperand(object_reg, HeapObject::kMapOffset),
            Immediate(to_map));
     // Write barrier.
     ASSERT_NE(instr->temp(), NULL);
     __ RecordWriteForMap(object_reg, to_map, new_map_reg,
                          ToRegister(instr->temp()),
                          kDontSaveFPRegs);
   } else {
+    ASSERT(ToRegister(instr->context()).is(esi));
     PushSafepointRegistersScope scope(this);
     if (!object_reg.is(eax)) {
-      __ push(object_reg);
-    }
-    LoadContextFromDeferred(instr->context());
-    if (!object_reg.is(eax)) {
-      __ pop(eax);
+      __ mov(eax, object_reg);
     }
     __ mov(ebx, to_map);
     TransitionElementsKindStub stub(from_kind, to_kind);
     __ CallStub(&stub);
     RecordSafepointWithRegisters(
         instr->pointer_map(), 0, Safepoint::kNoLazyDeopt);
   }
   __ bind(&not_applicable);
 }
 
@@ skipping 1566 matching lines @@
                               FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32