Turn Function.prototype.bind into a hydrogen stub optimized for the common case

src/builtins.cc

Index: src/builtins.cc
diff --git a/src/builtins.cc b/src/builtins.cc
index c596a9ca67d78858b52bf4ed98d27b058cd571ba..8d33428be5fc5743b3107ded7f790ebf3e601bc2 100644
--- a/src/builtins.cc
+++ b/src/builtins.cc
@@ -4238,9 +4238,10 @@ BUILTIN(FunctionConstructor) {
   return *result;
 }
 
+namespace {
 
-// ES6 section 19.2.3.2 Function.prototype.bind ( thisArg, ...args )
-BUILTIN(FunctionPrototypeBind) {
+Object* DoFunctionBind(Isolate* isolate,
+                       BuiltinArguments<BuiltinExtraArguments::kNone> args) {
   HandleScope scope(isolate);
   DCHECK_LE(1, args.length());
   if (!args.receiver()->IsCallable()) {
@@ -4324,6 +4325,22 @@ BUILTIN(FunctionPrototypeBind) {
   return *function;
 }
 
+}  // namespace
+
+// ES6 section 19.2.3.2 Function.prototype.bind ( thisArg, ...args )
+BUILTIN(FunctionPrototypeBind) { return DoFunctionBind(isolate, args); }
+
+// TODO(verwaest): This is a temporary helper until the FastFunctionBind stub
+// can tailcall to the builtin directly.
+RUNTIME_FUNCTION(Runtime_FunctionBind) {
+  DCHECK_EQ(2, args.length());
+  Arguments* incoming = reinterpret_cast<Arguments*>(args[0]);
+  // Rewrap the arguments as builtins arguments.
+  BuiltinArguments<BuiltinExtraArguments::kNone> caller_args(
+      incoming->length() + 1, incoming->arguments() + 1);
+  return DoFunctionBind(isolate, caller_args);
+}
+
 // ES6 section 19.2.3.5 Function.prototype.toString ( )
 BUILTIN(FunctionPrototypeToString) {
   HandleScope scope(isolate);