Inline AbstractFrame.page() since it shows in profiles and is a trivial getter.
Pull request: https://github.com/WebKit/WebKit/pull/10902
Committed 261078@main (7c82f53bc23f): <https://commits.webkit.org/261078@main> Reviewed commits have been landed. Closing PR #10902 and removing active labels.
<rdar://problem/106150200>