[builtins] Unify the various versions of [[Call]] with a Call builtin.

src/runtime/runtime-function.cc

Index: src/runtime/runtime-function.cc
diff --git a/src/runtime/runtime-function.cc b/src/runtime/runtime-function.cc
index a00ca4b73a7728436145eedee8c9c7ff6170f29b..51befeedbb6d7ebcfea2f1a13cb38d5f696704ee 100644
--- a/src/runtime/runtime-function.cc
+++ b/src/runtime/runtime-function.cc
@@ -16,6 +16,9 @@
 namespace v8 {
 namespace internal {
 
+// TODO(bmeurer): This is an awful hack resulting from our inability to decide
+// who's responsible for doing the receiver patching. By any means, we really
+// need to kill this runtime function and just do things right instead!!
 RUNTIME_FUNCTION(Runtime_IsSloppyModeFunction) {
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 1);