Noticed by code inspection that the map and compactMap functions are copying the collections passed to them. Add a test for this and fix it.
<rdar://problem/102000000>
Pull request: https://github.com/WebKit/WebKit/pull/6178
Committed 256373@main (7ea0a5456640): <https://commits.webkit.org/256373@main> Reviewed commits have been landed. Closing PR #6178 and removing active labels.