Reland "Add basic crankshaft support for slow-mode for-in to avoid disabling optimizations"

src/ia32/lithium-codegen-ia32.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #if V8_TARGET_ARCH_IA32
 
 #include "src/base/bits.h"
 #include "src/code-factory.h"
@@ skipping 5581 matching lines @@
   // backpatching it with the spill slot operands.
   DCHECK(!environment->HasBeenRegistered());
   RegisterEnvironmentForDeoptimization(environment, Safepoint::kNoLazyDeopt);
 
   GenerateOsrPrologue();
 }
 
 
 void LCodeGen::DoForInPrepareMap(LForInPrepareMap* instr) {
   DCHECK(ToRegister(instr->context()).is(esi));
-  __ cmp(eax, isolate()->factory()->undefined_value());
-  DeoptimizeIf(equal, instr, Deoptimizer::kUndefined);
-
-  __ cmp(eax, isolate()->factory()->null_value());
-  DeoptimizeIf(equal, instr, Deoptimizer::kNull);
-
   __ test(eax, Immediate(kSmiTagMask));
   DeoptimizeIf(zero, instr, Deoptimizer::kSmi);
 
   STATIC_ASSERT(FIRST_JS_PROXY_TYPE == FIRST_SPEC_OBJECT_TYPE);
   __ CmpObjectType(eax, LAST_JS_PROXY_TYPE, ecx);
   DeoptimizeIf(below_equal, instr, Deoptimizer::kWrongInstanceType);
 
   Label use_cache, call_runtime;
   __ CheckEnumCache(&call_runtime);
 
@@ skipping 126 matching lines @@
   CallRuntime(Runtime::kPushBlockContext, 2, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_IA32