The CpuProfile previously emitted a CpuProfileMaxSamplesCallbackTask
if there was a sample where V8 could not resolve the stack.

This resulted in a premature "samplebufferfull" events for the
self-profiling API.

Skipping over samples without a resolved stack solves this issue.

Bug: chromium:1334366
Change-Id: If7a375dbf533c391307e8e506b37c0e3705f63b2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3776680Reviewed-by: Patrick Thier <pthier@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#81871}