[Interpreter] Optimize equality check with null/undefined with a check on the map.

src/compiler/js-generic-lowering.cc

Index: src/compiler/js-generic-lowering.cc
diff --git a/src/compiler/js-generic-lowering.cc b/src/compiler/js-generic-lowering.cc
index 6738ddc165164fc2b193d4b12e15267accb1e5ef..dc4d6339f010020e48212816b5270a6e59fc773a 100644
--- a/src/compiler/js-generic-lowering.cc
+++ b/src/compiler/js-generic-lowering.cc
@@ -133,6 +133,10 @@ void JSGenericLowering::LowerJSStrictNotEqual(Node* node) {
                       Operator::kEliminatable);
 }
 
+void JSGenericLowering::LowerJSIsUndetectable(Node* node) {
+  UNREACHABLE();  // Should be replaced by ObjectIsUndetectable.

[rmcilroy, 2016/12/05 10:57:19]

Nit - in typed lowering.

[mythria, 2016/12/05 14:53:10]

Done.

+}
+
 void JSGenericLowering::LowerJSToBoolean(Node* node) {
   // The ToBoolean conversion doesn't need the current context.
   NodeProperties::ReplaceContextInput(node, jsgraph()->NoContextConstant());