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

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

Index: src/crankshaft/arm64/lithium-codegen-arm64.cc
diff --git a/src/crankshaft/arm64/lithium-codegen-arm64.cc b/src/crankshaft/arm64/lithium-codegen-arm64.cc
index 06dc1c641f2fde00e08faddebc06f80c0953160d..c865a08ec85312d102d8f6642f64942b040eaa4c 100644
--- a/src/crankshaft/arm64/lithium-codegen-arm64.cc
+++ b/src/crankshaft/arm64/lithium-codegen-arm64.cc
@@ -5544,7 +5544,7 @@ void LCodeGen::DoTypeofIsAndBranch(LTypeofIsAndBranch* instr) {
     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));