Stop using Vector::unsafeAppendWithoutCapacityCheck() in B3IRGenerator::addLocal().
Pull request: https://github.com/WebKit/WebKit/pull/20458
Committed 270704@main (38f33ee36da1): <https://commits.webkit.org/270704@main> Reviewed commits have been landed. Closing PR #20458 and removing active labels.
<rdar://problem/118391287>