runtime: non-strict InlTreeIndex lookup in expandFinalInlineFrame
runtime: non-strict InlTreeIndex lookup in expandFinalInlineFrame

This is a follow-up to golang.org/cl/301369, which made the same change
in Frames.Next. The same logic applies here: a profile stack may have
been truncated at an invalid PC provided by cgoTraceback.
expandFinalInlineFrame will then try to lookup the inline tree and
crash.

The same fix applies as well: upon encountering a bad PC, simply leave
it as-is and move on.

Fixes #44971
Fixes #45480

Change-Id: I2823c67a1f3425466b05384cc6d30f5fc8ee6ddc
Reviewed-on: https://go-review.googlesource.com/c/go/+/309109
Reviewed-by: Michael Knyszek <4473450dc5c88f06e1fb787f303d7805ec2aee65@google.com>
Trust: Michael Pratt <e7f1edc6d5aa9f6c8c377425db8f1a5816cbbb88@google.com>

CAFxX/go,CAFxX/go,golang/go,cloudflare/go,golang/go,CAFxX/go,cloudflare/go,nawawi/go,nawawi/go,CAFxX/go,golang/go,cloudflare/go,cloudflare/go,golang/go,golang/go,nawawi/go,cloudflare/go,nawawi/go,CAFxX/go,cloudflare/go,golang/go,cloudflare/go,CAFxX/go,golang/go,CAFxX/go,nawawi/go,nawawi/go,golang/go,cloudflare/go,nawawi/go,nawawi/go,CAFxX/go