[es6] Reintroduce the instanceof operator in the backends.

src/full-codegen/mips64/full-codegen-mips64.cc

Index: src/full-codegen/mips64/full-codegen-mips64.cc
diff --git a/src/full-codegen/mips64/full-codegen-mips64.cc b/src/full-codegen/mips64/full-codegen-mips64.cc
index 8e69ca5317ea3192e815557e833d7ef3a67465ea..92512108f746f8699c1aba7168e1f936f4420d0e 100644
--- a/src/full-codegen/mips64/full-codegen-mips64.cc
+++ b/src/full-codegen/mips64/full-codegen-mips64.cc
@@ -3150,12 +3150,6 @@ void FullCodeGenerator::EmitGetSuperConstructor(CallRuntime* expr) {
   context()->Plug(v0);
 }
 
-void FullCodeGenerator::EmitGetOrdinaryHasInstance(CallRuntime* expr) {
-  DCHECK_EQ(0, expr->arguments()->length());
-  __ LoadNativeContextSlot(Context::ORDINARY_HAS_INSTANCE_INDEX, v0);
-  context()->Plug(v0);
-}
-
 void FullCodeGenerator::EmitDebugIsActive(CallRuntime* expr) {
   DCHECK(expr->arguments()->length() == 0);
   ExternalReference debug_is_active =