When deserializing from a code snapshot with logging enabled (e.g. when
profiling) then this ensures source positions are collected before
creating code events that need them.

Bug: chromium:994673, v8:9504
Change-Id: Iad7644e983d3004c4889615cf2104dc4ef40da46
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1762023Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63286}