function table, mangle the pointers.
* sysdeps/pthread/pthread-functions.h: Define PTHFCT_CALL.
* forward.c: Use PTHFCT_CALL and __libc_pthread_functions_init.
* sysdeps/pthread/bits/libc-lock.h: When using __libc_pthread_functions
demangle pointers before use.
* sysdeps/unix/sysv/linux/s390/jmp-unwind.c: Use PTHFCT_CALL to
demangle pointer.
* sysdeps/unix/sysv/linux/jmp-unwind.c: Likewise.
* sysdeps/pthread/setxid.h: Likewise.