[es6] Reintroduce the instanceof operator in the backends.

src/builtins.cc

Index: src/builtins.cc
diff --git a/src/builtins.cc b/src/builtins.cc
index 77d4b3a87ce68835eddc4bdc0a21eb90481ab5f8..8365c86048b237843269fe69460a7e10e8fe96f4 100644
--- a/src/builtins.cc
+++ b/src/builtins.cc
@@ -2394,6 +2394,21 @@ void Builtins::Generate_MathTrunc(CodeStubAssembler* assembler) {
 }
 
 // -----------------------------------------------------------------------------
+// ES6 section 19.2 Function Objects
+
+// ES6 section 19.2.3.6 Function.prototype [ @@hasInstance ] ( V )
+void Builtins::Generate_FunctionPrototypeHasInstance(
+    CodeStubAssembler* assembler) {
+  using compiler::Node;
+
+  Node* f = assembler->Parameter(0);
+  Node* v = assembler->Parameter(1);
+  Node* context = assembler->Parameter(4);
+  Node* result = assembler->OrdinaryHasInstance(context, f, v);
+  assembler->Return(result);
+}
+
+// -----------------------------------------------------------------------------
 // ES6 section 25.3 Generator Objects
 
 namespace {
@@ -4197,7 +4212,6 @@ BUILTIN(FunctionPrototypeBind) {
   return *function;
 }
 
-
 // ES6 section 19.2.3.5 Function.prototype.toString ( )
 BUILTIN(FunctionPrototypeToString) {
   HandleScope scope(isolate);