In ShortPrint, print a # before a string's length if it is internalized

Change-Id: Ifed80b358a4502c72d8a3d08b3b9399afe308d0f
Reviewed-on: https://chromium-review.googlesource.com/c/1411539Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58826}