Another thing to check. This code in Perl_flex_stat looks worrisome to me:
#ifdef _USE_STD_STAT
memcpy(&statbufp->st_ino, &statbufp->crtl_stat.st_ino, 8);
#else
memcpy(&statbufp->st_ino, statbufp->crtl_stat.st_ino, 8);
#endif
It seems to me that when _USE_STD_STAT is not in effect, we should only be
copying 6 bytes, not 8. That and/or the fact that my_ino_t in vmsish.h is only
declared to be 32 bits instead of 48, which we appear to expect in some places.
I could well be missing something and won't be near my debugging tools until
late tonight.