Suppress HAC ref-bind notices when setting up fb_intercept

Summary: It's doing an `appendRef` but the array isn't leaking anywhere, it's just being used in `invokeFunc`. The argument array (which gets created with `appendWithRef` does leak to the function doing an intercept but only contains refs when intercepting a function that's already pass-by-ref.

Reviewed By: ricklavoie

Differential Revision: D14961879

fbshipit-source-id: e236bdf60d55859bc528a95e15d591351cc8581d

hphp/runtime/vm/event-hook.cpp

@@ -223,6 +223,7 @@ static Array get_frame_args_with_ref(const ActRec* ar) {
   int numNonVariadic = ar->func()->numNonVariadicParams();
   int numArgs = ar->numArgs();
 
+  SuppressHACRefBindNotices _guard;
   PackedArrayInit retArray(numArgs);
 
   auto local = reinterpret_cast<TypedValue*>(
@@ -301,6 +302,7 @@ static Variant call_intercept_handler(
     }
     intArgs = par.append(done).toArray();
   } else {
+    SuppressHACRefBindNotices _guard;
     Variant tmp;
     tmp.assignRef(done);
     intArgs = par.appendWithRef(tmp).toArray();

hphp/test/slow/intercept/hac-warnings.php

@@ -0,0 +1,12 @@
+<?hh
+
+<<__NEVER_INLINE>>
+function foo() {}
+
+function intercept($n) { var_dump($n); }
+
+<<__EntryPoint>>
+function main() {
+  fb_intercept('foo', 'intercept');
+  foo();
+}

hphp/test/slow/intercept/hac-warnings.php.expect

@@ -0,0 +1 @@
+string(3) "foo"

hphp/test/slow/intercept/hac-warnings.php.hphp_opts

@@ -0,0 +1 @@
+-vJitEnableRenameFunction=1 -vHackArrCompatNotices=1

hphp/test/slow/intercept/hac-warnings.php.opts

@@ -0,0 +1 @@
+-vEval.HackArrCompatNotices=1 -vEval.HackArrCompatCheckRefBind=1