[Interpreter] Add CallRuntime support to the interpreter.

src/code-factory.cc

Index: src/code-factory.cc
diff --git a/src/code-factory.cc b/src/code-factory.cc
index cfa11a7e62371aff04700b5f91f8153efaf5aba8..671c74b206ce8906f9b07325b050da449e84ea95 100644
--- a/src/code-factory.cc
+++ b/src/code-factory.cc
@@ -269,9 +269,19 @@ Callable CodeFactory::CallFunction(Isolate* isolate, int argc,
 
 
 // static
-Callable CodeFactory::PushArgsAndCall(Isolate* isolate) {
-  return Callable(isolate->builtins()->PushArgsAndCall(),
-                  PushArgsAndCallDescriptor(isolate));
+Callable CodeFactory::InterpreterPushArgsAndCall(Isolate* isolate) {
+  return Callable(isolate->builtins()->InterpreterPushArgsAndCall(),
+                  InterpreterPushArgsAndCallDescriptor(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));
 }
 
 }  // namespace internal