Add machinery to support arguments escaping to safe builtins

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 63fb13be99739d6344726f3882629bf44d955240..7ee58ba02d7c7440ff0b644c00c83a51ab9cdcc9 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -9877,6 +9877,15 @@ void SharedFunctionInfo::TrimOptimizedCodeMap(int shrink_by) {
 }
 
 
+bool SharedFunctionInfo::CanHandleArgumentsSafely() {
+  if (!HasBuiltinFunctionId()) return false;
+  switch (builtin_function_id()) {
+    default: return false;
+  }
+  UNREACHABLE();
+}
+
+
 void JSObject::OptimizeAsPrototype(Handle<JSObject> object) {
   if (object->IsGlobalObject()) return;