Tail call from TurboFan into select runtime calls

src/runtime/runtime.cc

Index: src/runtime/runtime.cc
diff --git a/src/runtime/runtime.cc b/src/runtime/runtime.cc
index 674f1173a789446cd138c8fa3c17c7c7baa06285..0d6b708391d468449eb2a3416298f6c92bcae2cf 100644
--- a/src/runtime/runtime.cc
+++ b/src/runtime/runtime.cc
@@ -90,6 +90,18 @@ const Runtime::Function* Runtime::FunctionForId(Runtime::FunctionId id) {
 }
 
 
+bool Runtime::SupportsTailCall(FunctionId id) {
+  switch (id) {
+#define RUNTIME_FUNCTION_SWITCH(name, a, b) case k##name:
+    FOR_EACH_INTRINSIC_IC(RUNTIME_FUNCTION_SWITCH)
+#undef RUNTIME_FUNCTION_SWITCH
+    return true;
+    default:
+      return false;
+  }
+}
+
+
 std::ostream& operator<<(std::ostream& os, Runtime::FunctionId id) {
   return os << Runtime::FunctionForId(id)->name;
 }