[Interpreter] Add support for calling runtime functions which return a pair.

src/code-factory.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/code-factory.h"
 
 #include "src/bootstrapper.h"
 #include "src/ic/ic.h"
 
 namespace v8 {
@@ skipping 342 matching lines @@
 
 // static
 Callable CodeFactory::InterpreterPushArgsAndConstruct(Isolate* isolate) {
   return Callable(isolate->builtins()->InterpreterPushArgsAndConstruct(),
                   InterpreterPushArgsAndConstructDescriptor(isolate));
 }
 
 
 // static
 Callable CodeFactory::InterpreterCEntry(Isolate* isolate) {
-  // TODO(rmcilroy): Deal with runtime functions that return two values.
   // Note: If we ever use fpregs in the interpreter then we will need to
   // save fpregs too.
   CEntryStub stub(isolate, 1, kDontSaveFPRegs, kArgvInRegister);
   return Callable(stub.GetCode(), InterpreterCEntryDescriptor(isolate));
 }
 
+
+// static
+Callable CodeFactory::InterpreterCEntryPair(Isolate* isolate) {
+  // Note: If we ever use fpregs in the interpreter then we will need to
+  // save fpregs too.
+  CEntryStub stub(isolate, 2, kDontSaveFPRegs, kArgvInRegister);
+  return Callable(stub.GetCode(), InterpreterCEntryDescriptor(isolate));
+}
+
 }  // namespace internal
 }  // namespace v8