[turbofan] Make %Arguments composable with inlining.

src/runtime/runtime.h

Index: src/runtime/runtime.h
diff --git a/src/runtime/runtime.h b/src/runtime/runtime.h
index 88cd36323399837ce0f9bca5474ce9c19e605a62..2edf7e1f475d69b4a23d4a1b8785a90a9344d4b0 100644
--- a/src/runtime/runtime.h
+++ b/src/runtime/runtime.h
@@ -1177,6 +1177,7 @@ class Runtime : public AllStatic {
       Isolate* isolate, Handle<Object> receiver_obj, Handle<Object> key_obj,
       LanguageMode language_mode);
 
+  // TODO(mstarzinger): Remove this once %DefaultConstructorCallSuper is gone.
   MUST_USE_RESULT static MaybeHandle<Object> GetPrototype(
       Isolate* isolate, Handle<Object> object);
 
@@ -1207,6 +1208,15 @@ class Runtime : public AllStatic {
   static MaybeHandle<JSArray> GetInternalProperties(Isolate* isolate,
                                                     Handle<Object>);
 
+  // Find the arguments of the JavaScript function invocation that called
+  // into C++ code. Collect these in a newly allocated array of handles
+  // (possibly prefixed by a number of empty handles).
+  // TODO(mstarzinger): Temporary workaround until this is only used by the
+  // %_Arguments and %_ArgumentsLength intrinsics. Make this function local to
+  // runtime-scopes.cc then.
+  static base::SmartArrayPointer<Handle<Object>> GetCallerArguments(
+      Isolate* isolate, int prefix_argc, int* total_argc);
+
   static bool AtomicIsLockFree(uint32_t size);
 };