Mark null and undefined as undetectable, and use it to handle abstract equality comparison in the g…

src/crankshaft/arm64/lithium-codegen-arm64.cc

 // Copyright 2013 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/crankshaft/arm64/lithium-codegen-arm64.h"
 
 #include "src/arm64/frames-arm64.h"
 #include "src/base/bits.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
@@ skipping 5526 matching lines @@
 
   } else if (String::Equals(type_name, factory->boolean_string())) {
     __ JumpIfRoot(value, Heap::kTrueValueRootIndex, true_label);
     __ CompareRoot(value, Heap::kFalseValueRootIndex);
     EmitBranch(instr, eq);
 
   } else if (String::Equals(type_name, factory->undefined_string())) {
     DCHECK(instr->temp1() != NULL);
     Register scratch = ToRegister(instr->temp1());
 
-    __ JumpIfRoot(value, Heap::kUndefinedValueRootIndex, true_label);
+    __ JumpIfRoot(value, Heap::kNullValueRootIndex, false_label);
     __ JumpIfSmi(value, false_label);
     // Check for undetectable objects and jump to the true branch in this case.
     __ Ldr(scratch, FieldMemOperand(value, HeapObject::kMapOffset));
     __ Ldrb(scratch, FieldMemOperand(scratch, Map::kBitFieldOffset));
     EmitTestAndBranch(instr, ne, scratch, 1 << Map::kIsUndetectable);
 
   } else if (String::Equals(type_name, factory->function_string())) {
     DCHECK(instr->temp1() != NULL);
     Register scratch = ToRegister(instr->temp1());
 
@@ skipping 187 matching lines @@
   Handle<ScopeInfo> scope_info = instr->scope_info();
   __ Push(scope_info);
   __ Push(ToRegister(instr->function()));
   CallRuntime(Runtime::kPushBlockContext, instr);
   RecordSafepoint(Safepoint::kNoLazyDeopt);
 }
 
 
 }  // namespace internal
 }  // namespace v8