[es6] Reintroduce the instanceof operator in the backends.

src/mips/builtins-mips.cc

Index: src/mips/builtins-mips.cc
diff --git a/src/mips/builtins-mips.cc b/src/mips/builtins-mips.cc
index aff49b6a8a954b443ebac12cec0f2940390a7d41..cc1baa23bf061f1cda172f3fe5e30ed9f819f5fb 100644
--- a/src/mips/builtins-mips.cc
+++ b/src/mips/builtins-mips.cc
@@ -1747,28 +1747,6 @@ void Builtins::Generate_DatePrototype_GetField(MacroAssembler* masm,
 }
 
 // static
-void Builtins::Generate_FunctionHasInstance(MacroAssembler* masm) {
-  // ----------- S t a t e -------------
-  //  -- a0    : argc
-  //  -- sp[0] : first argument (left-hand side)
-  //  -- sp[4] : receiver (right-hand side)
-  // -----------------------------------
-
-  {
-    FrameScope scope(masm, StackFrame::INTERNAL);
-    __ lw(InstanceOfDescriptor::LeftRegister(),
-          MemOperand(fp, 2 * kPointerSize));  // Load left-hand side.
-    __ lw(InstanceOfDescriptor::RightRegister(),
-          MemOperand(fp, 3 * kPointerSize));  // Load right-hand side.
-    InstanceOfStub stub(masm->isolate(), true);
-    __ CallStub(&stub);
-  }
-
-  // Pop the argument and the receiver.
-  __ DropAndRet(2);
-}
-
-// static
 void Builtins::Generate_FunctionPrototypeApply(MacroAssembler* masm) {
   // ----------- S t a t e -------------
   //  -- a0    : argc