deps: backport f782159 from v8's upstream

Backport f78215962bf5de9d47c022e7baa3952d0bf6d17f from V8's upstream
to speed up promise introspection.

Original commit message:

  Remove obsolete try/catch from ObjectIsPromise().

  Review URL: https://codereview.chromium.org/1367123003

  Cr-Commit-Position: refs/heads/master@{#30966}

PR-URL: #3130
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>

deps/v8/src/mirror-debugger.js

@@ -19,16 +19,9 @@ function ToggleMirrorCache(value) {
 }
 
 
-// Wrapper to check whether an object is a Promise.  The call may not work
-// if promises are not enabled.
-// TODO(yangguo): remove try-catch once promises are enabled by default.
 function ObjectIsPromise(value) {
-  try {
-    return IS_SPEC_OBJECT(value) &&
-           !IS_UNDEFINED(%DebugGetProperty(value, builtins.$promiseStatus));
-  } catch (e) {
-    return false;
-  }
+  return IS_SPEC_OBJECT(value) &&
+         !IS_UNDEFINED(%DebugGetProperty(value, builtins.$promiseStatus));
 }