Initial ZendMM conversion of glob

[NattyNarwhal]

Removes the vendored OpenBSD reallocarray and changes libc memory management to ZendMM.

Not sure if non-persistent is the right call, I think glob users use it then call globfree ASAP within a request, but it might be preferable to use persistent allocations.

[bukka]

About the persistence, it should not be persistent so it counts against memory limit which is the main point in changing this. But you should of course check all the usage and make sure it is never user outside the request or re-used between request - it shouldn't but better to check.

[bukka]

I'm also not sure about the glob limits (for malloc and others). It might be good to check if glibc have similar limits to see if they should be kept - doesn't need to be changed as part of this PR but would make sense to look into before switching to it on Linux as well.

[NattyNarwhal]

About the persistence, it should not be persistent so it counts against memory limit which is the main point in changing this. But you should of course check all the usage and make sure it is never user outside the request or re-used between request - it shouldn't but better to check.

In the places glob is used:

ext/ffi/ffi.c:  ret = glob(filename, 0, NULL, &globbuf);
ext/opcache/zend_accelerator_blacklist.c:       ret = glob(filename, 0, NULL, &globbuf);
ext/standard/dir.c:     if (0 != (ret = glob(pattern, flags & GLOB_FLAGMASK, NULL, &globbuf))) {
ext/zip/php_zip.c:      if (0 != (ret = glob(pattern, flags & GLOB_FLAGMASK, NULL, &globbuf))) {
main/streams/glob_wrapper.c:    if (0 != (ret = glob(pattern, pglob->flags & GLOB_FLAGMASK, NULL, &pglob->glob))) {
sapi/fpm/fpm/fpm_conf.c:                if ((i = glob(inc, GLOB_ERR | GLOB_MARK, NULL, &g)) != 0) {

...all instances of it call globfree in the same function, with the exception of the glob stream wrapper.