Bug 1598869: Avoid unused function warning for Promise.any. r=jorendorff

Only define `Promise_static_any` when `NIGHTLY_BUILD` to avoid an unused
function warning.

Differential Revision: https://phabricator.services.mozilla.com/D54697

--HG--
extra : moz-landing-system : lando

js/src/builtin/Promise.cpp

@@ -3539,6 +3539,7 @@ static bool PromiseAllSettledElementFunction(JSContext* cx, unsigned argc,
   return true;
 }
 
+#ifdef NIGHTLY_BUILD
 // Promise.any (Stage 3 proposal)
 // https://tc39.es/proposal-promise-any/
 //
@@ -3547,6 +3548,7 @@ static bool Promise_static_any(JSContext* cx, unsigned argc, Value* vp) {
   CallArgs args = CallArgsFromVp(argc, vp);
   return CommonPromiseCombinator(cx, args, CombinatorKind::Any);
 }
+#endif
 
 // Promise.any (Stage 3 proposal)
 // https://tc39.es/proposal-promise-any/