Use window.QUnit to detect the top window when loading with AMD
Pass all tests (and load Sizzle fixture correctly) when loading with AMD
Fix #14318: Cherry-pick interrupted animation fix from master ea5c22ec12e6a548b1ec2d7b0dcd9f71bea8d5dd
Merge remote-tracking branch 'upstream/master' into grep-test

* upstream/master:
  Fix #14318: Cherry-pick interrupted animation fix from master ea5c22ec12e6a548b1ec2d7b0dcd9f71bea8d5dd
  Pass all tests (and load Sizzle fixture correctly) when loading with AMD
  Use window.QUnit to detect the top window when loading with AMD