[PurHur]

Summary

• Implement JIT/AOT lowering for strxfrm() in ext/standard/strxfrm.php using libc strxfrm(3) two-pass sizing (php-src: ext/standard/string.c).
• Register strxfrm libc symbol in ext/standard/Module.php alongside strcoll.
• Add JIT compliance (strxfrm_jit.phpt) and AOT fixture (test/fixtures/aot/cases/strxfrm.phpt).

Closes #4376

Verification

./script/docker-exec.sh -- bash -lc 'php script/capability-matrix.php'
./script/docker-exec.sh -- bash -lc './vendor/bin/phpunit --filter "strcoll_strxfrm|strxfrm"'
./script/docker-exec.sh -- bash -lc './vendor/bin/phpunit --filter "AotTest.*strxfrm"'
./script/docker-exec.sh -- bash -lc 'php bin/compile.php -l test/fixtures/aot/compile-only/strcoll_strxfrm.php'

Output:

OK (8 tests, 13 assertions)   # VM + JIT compliance
OK (1 test, 5 assertions)     # AOT fixture

Made with Cursor