This retrieves script name directly from StackFrameBase, bypassing
building of StackFrameInfo if one hasn't already been initialized,
thus avoiding computation of expensive properties that are not
required. This matches current behavior of GetScriptNameOrSourceURL()
and is a workaround until a dedicated API is available.

Bug: chromium:1098530
Change-Id: I181dc7feeebaf2f45758bbd29be24ab036e44b19
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2261736Reviewed-by: Simon Zünd <szuend@chromium.org>
Commit-Queue: Alex Turner <alexmt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68543}