radar has a concept of "sourceChanges" which track where in source code a fix for a particular issue has been made. We eventually need to represent the same idiom in Bugzilla and GitHub Issues, for now, just support the radar version of the idiom so that tools can modify and query this field.
<rdar://problem/106808712>
Pull request: https://github.com/WebKit/WebKit/pull/11607
Committed 277553@main (1517cb01bf1f): <https://commits.webkit.org/277553@main> Reviewed commits have been landed. Closing PR #11607 and removing active labels.