Add tests for uncastable streams and dataloss streams (#10173)

And suppress the nonsensical warnings by passing the PHP_STREAM_CAST_INTERNAL flag.

posix detects posix_pathconf api.

alpine linux throws undefined reference at build time, thus
not assuming it s necessarily available.

Closes GH-10350.

posix adding posix_fpathconf.

follow-up on GH-10238 but with the file descriptor flavor.

Close GH-10253