When getting the starting address of a data segment, you can't use
`&vector[offset]` if offset is equal to the length of the vector. This
can happen when the length of the segment is 0.

The fix is to use Vector::SubVector instead.

Bug: v8:9106
Change-Id: Icf8968cc246c6d217d8061f76fb2631c2292433c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1560405
Commit-Queue: Ben Smith <binji@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60755}