Fix extra PLT reference in libc.so due to __glob64_time64 if build with gcc 7.5 on 32bit.

Starting with recent commit 84f7ce84
"posix: Add glob64 with 64-bit time_t support", elf/check-localplt
fails due to extra PLT reference __glob64_time64 in __glob64_time64
itself.

This is observable with gcc 7.5 on x86_64 with -m32 or s390x with
-m31.  E.g. if build with gcc 10, gcc is generating a call to
__glob64_time64.localalias.

This patch is adding a hidden version of __glob64_time64 in the
same way as for __globfree64_time64.