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

src/code-factory.cc

Index: src/code-factory.cc
diff --git a/src/code-factory.cc b/src/code-factory.cc
index 949bf9ab9c9db30155785457c92fbdf1172d87fd..6d31a5f530dc137f2c11c77ea0022d2ca0a1c64c 100644
--- a/src/code-factory.cc
+++ b/src/code-factory.cc
@@ -359,11 +359,10 @@ Callable CodeFactory::InterpreterPushArgsAndConstruct(Isolate* isolate) {
 
 
 // static
-Callable CodeFactory::InterpreterCEntry(Isolate* isolate) {
-  // TODO(rmcilroy): Deal with runtime functions that return two values.
+Callable CodeFactory::InterpreterCEntry(Isolate* isolate, int result_size) {
   // Note: If we ever use fpregs in the interpreter then we will need to
   // save fpregs too.
-  CEntryStub stub(isolate, 1, kDontSaveFPRegs, kArgvInRegister);
+  CEntryStub stub(isolate, result_size, kDontSaveFPRegs, kArgvInRegister);
   return Callable(stub.GetCode(), InterpreterCEntryDescriptor(isolate));
 }