Stop using _LFS64_LARGEFILE

There is only one place left in the code where strace guesses whether
libc provides LFS64 functions and structures.  The most natural thing to
do there is to check for _LARGEFILE64_SOURCE - the macro provided by
glibc.  Other libc implementations that provide nondegenerate LFS64
interfaces are expected to define this macro as well.

* defs.h (_LFS64_LARGEFILE): Remove.
* strace.c: Use _LARGEFILE64_SOURCE instead of _LFS64_LARGEFILE.
2 files changed