Extend stress source positions to also ensure source positions for eagerly
compiled inner functions when lazily compiling the outer function.

BUG=v8:8510

Change-Id: I66d04beb789f13c15ed87cf10f606723c18f5d8f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1774725
Commit-Queue: Dan Elphick <delphick@chromium.org>
Auto-Submit: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63482}