[turbofan] First step towards sanitizing for-in and making it optimizable.

src/x64/full-codegen-x64.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_X64
 
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 1213 matching lines @@
   // For proxies, no filtering is done.
   // TODO(rossberg): What if only a prototype is a proxy? Not specified yet.
   __ Cmp(rdx, Smi::FromInt(0));
   __ j(equal, &update_each, Label::kNear);
 
   // Convert the entry to a string or null if it isn't a property
   // anymore. If the property has been removed while iterating, we
   // just skip it.
   __ Push(rcx);  // Enumerable.
   __ Push(rbx);  // Current entry.
-  __ InvokeBuiltin(Builtins::FILTER_KEY, CALL_FUNCTION);
+  __ CallRuntime(Runtime::kForInFilter, 2);
   PrepareForBailoutForId(stmt->FilterId(), TOS_REG);
-  __ Cmp(rax, Smi::FromInt(0));
+  __ CompareRoot(rax, Heap::kUndefinedValueRootIndex);
   __ j(equal, loop_statement.continue_label());
   __ movp(rbx, rax);
 
   // Update the 'each' property or variable from the possibly filtered
   // entry in register rbx.
   __ bind(&update_each);
   __ movp(result_register(), rbx);
   // Perform the assignment as if via '='.
   { EffectContext context(this);
     EmitAssignment(stmt->each(), stmt->EachFeedbackSlot());
@@ skipping 4204 matching lines @@
   DCHECK_EQ(isolate->builtins()->OsrAfterStackCheck()->entry(),
             Assembler::target_address_at(call_target_address,
                                          unoptimized_code));
   return OSR_AFTER_STACK_CHECK;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64