When the file begins with a hashbang, the scanner is in a failed state
when SkipHashbang() is called. This is usually not an issue but when
the parser encounters an ILLEGAL token, it will reset the SyntaxError
location because of it.

Bug: v8:10110
Change-Id: I1c7344bf5ad20079cff80130c991f3bff4d7e9a8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1995312Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66038}