This updates the InterfaceDescriptor for JSRunMicrotasksEntry and
RunMicrotasksTrampoline from DummyDescriptor to RunMicrotasksEntryDescriptor.

Bug: v8:8124
Change-Id: I4522fd45bd18b33a2a4471b76c217d2a0f504cb0
Reviewed-on: https://chromium-review.googlesource.com/c/1412132
Commit-Queue: Taiju Tsuiki <tzik@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58879}