Merge branch 'cl/regexec-macos-leak' into jch

A compatibility workaround has been introduced for macOS to address a memory leak in the system regex engine when it encounters invalid multibyte sequences. The workaround segments the input buffer at invalid byte boundaries and searches each valid segment separately using regexec(), avoiding the leaking path. * cl/regexec-macos-leak: SQUASH??? regexec: work around macOS TRE leak on invalid UTF-8