Fix register mixup in arm64's Crankshafted typeof() == 'object'

R=ulan@chromium.org

Review URL: https://codereview.chromium.org/330593003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21798 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm64/lithium-codegen-arm64.cc

@@ -5896,7 +5896,7 @@ void LCodeGen::DoTypeofIsAndBranch(LTypeofIsAndBranch* instr) {
     __ CompareInstanceType(map, scratch, LAST_NONCALLABLE_SPEC_OBJECT_TYPE);
     __ B(gt, false_label);
     // Check for undetectable objects => false.
-    __ Ldrb(scratch, FieldMemOperand(value, Map::kBitFieldOffset));
+    __ Ldrb(scratch, FieldMemOperand(map, Map::kBitFieldOffset));
     EmitTestAndBranch(instr, eq, scratch, 1 << Map::kIsUndetectable);
 
   } else {