Clean up dead code after spread desugaring

src/contexts.cc

Index: src/contexts.cc
diff --git a/src/contexts.cc b/src/contexts.cc
index 79a9e926a560135266f2c6aa1124dbabb58d003e..dc4c0bd2c6f659775d734db0f6187eb80ebf2c16 100644
--- a/src/contexts.cc
+++ b/src/contexts.cc
@@ -542,16 +542,6 @@ int Context::IntrinsicIndexForName(Handle<String> string) {
 #undef COMPARE_NAME
 
 
-bool Context::IsJSBuiltin(Handle<Context> native_context,
-                          Handle<JSFunction> function) {
-#define COMPARE_FUNCTION(index, type, name) \
-  if (*function == native_context->get(index)) return true;
-  NATIVE_CONTEXT_JS_BUILTINS(COMPARE_FUNCTION);
-#undef COMPARE_FUNCTION
-  return false;
-}
-
-
 #ifdef DEBUG
 
 bool Context::IsBootstrappingOrNativeContext(Isolate* isolate, Object* object) {