ext/posix: (Further) fix groups array creation on macos.

With macos Tahoe and clang "17.0.0" (Xcode) the ext/posix/tests/posix_getgrgid_macosx.phpt test crashes as follow:

ext/posix/posix.c:681:19: runtime error: load of misaligned address 0x60800000e972 for type 'char **', which requires 8 byte alignment
0x60800000e972: note: pointer points here
70 00  2a 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  00 00 00 00 00 00
seems memcpy had been translated to a load instruction ?
anyhow, we force to copy a "proper" char * source.

Author: devnexen

ext/posix/posix.c

@@ -676,9 +676,10 @@ int php_posix_group_to_array(struct group *g, zval *array_group) /* {{{ */
 		add_assoc_null(array_group, "passwd");
 	}
 	for (count = 0;; count++) {
+		char *entry = (char *)g->gr_mem + (count * sizeof (char *));
 		/* gr_mem entries may be misaligned on macos. */
 		char *gr_mem;
-		memcpy(&gr_mem, &g->gr_mem[count], sizeof(char *));
+		memcpy(&gr_mem, entry, sizeof(char *));
 		if (!gr_mem) {
 			break;
 		}