AOT: integer overflow promotes to float on + and * (#31964)

[PurHur]

Summary

• Add lib/JIT/JitLongArithOverflow.php implementing Zend ZEND_SIGNED_ADD_OVERFLOW / ZEND_LONG_MUL_OVERFLOW for JIT/AOT long arithmetic.
• Wire overflow promotion into native-long pairs in Helper.php and boxed numeric paths in JitValueNumeric.php.
• Repro + compliance .phpt and targeted JIT/AOT PHPUnit guards.

Closes #31964

php-src reference

• Zend/zend_operators.h — ZEND_SIGNED_ADD_OVERFLOW, ZEND_LONG_MUL_OVERFLOW
• Zend/zend_operators.c — add_function / mul_function

Verification

./script/docker-exec.sh -- bash -lc 'php bin/vm.php test/repro/maintainer_gap_aot_int_overflow.php'
# float(9.223372036854776E+18)
# float(1.8446744073709552E+19)

./script/docker-exec.sh -- bash -lc 'php bin/compile.php -o /tmp/int_overflow test/repro/maintainer_gap_aot_int_overflow.php && /tmp/int_overflow'
# float(9.2233720368548e+18)  — same value, AOT var_dump formatting differs slightly
# float(1.844674407371e+19)

./script/phpunit.sh --filter IntArithOverflowPromote31964JITTest
# OK (1 test)

./script/phpunit.sh --filter IntArithOverflowPromote31964AotTest
# OK (1 test)

Not covered

• Related rows in AOT: integer overflow wraps instead of promoting to float — silent wrong arithmetic #31964 (const-folded 7/2, $x++ on float, % edge cases, cast-as-arg NULL) — separate causes, not changed here.
• Full compliance / differential sweep.

Made with Cursor