Attach SourcePositionInfo objects to existing code entries if we find
code-source-info log entries. This improves fixes finding scripts for
anonymous functions.

Bug: v8:10644
Change-Id: I6fc1e029b17107cacce89dc74a67d4d448d9a979
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2562672
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Sathya Gunasekaran  <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71482}