Avoid string comparison in HTMLConstructionSite::setCompatibilityModeFromDoctype() in common case where the doc type is "html".
Pull request: https://github.com/WebKit/WebKit/pull/3813
Committed 253970@main (819d53409c99): <https://commits.webkit.org/253970@main> Reviewed commits have been landed. Closing PR #3813 and removing active labels.
<rdar://problem/99361559>