Revert "Replace zero-length array decls with []."

Revert "Replace zero-length array decls with []."

This reverts 6c5f9baa3bc0d63e141e0afc23110205379905a4 commit, whose
change breaks gcc-2.95.

Not that I ignore portability to compilers that are properly C99, but
keeping compilation with GCC working is more important, at least for
now.  We would probably end up declaring with "name[1]" and teach the
allocator to subtract one if we really aimed for portability, but that
is left for later rounds.

Signed-off-by: Junio C Hamano <junkio@cox.net>