JS script names in debug info entries need to be null-terminated, the
terminator included in the length. However, SeqOneByteString's GetChars
returns raw pointer that's not null terminated.

Bug: chromium:1159164
Change-Id: Id00f72dc831fa1ae48a458a1d4476ada4730be54
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2593345Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Pierre Langlois <pierre.langlois@arm.com>
Cr-Commit-Position: refs/heads/master@{#71795}