remove gdb_dirent.h

remove gdb_dirent.h

This removes gdb_dirent.h and updates the code to use dirent.h
instead.  It also removes the now-useless configure checks.

2013-11-18  Tom Tromey  <tromey@redhat.com>

	* common/common.m4 (GDB_AC_COMMON): Don't use AC_HEADER_DIRENT.
	* common/gdb_dirent.h: Remove.
	* common/filestuff.c: Use dirent.h.
	* common/linux-osdata.c: Use dirent.h.
	(NAMELEN): Define.
	* config.in: Rebuild.
	* configure: Rebuild.
	* configure.ac: Don't use AC_HEADER_DIRENT.
	* linux-fork.c: Use dirent.h
	* linux-nat.c: Use dirent.h.
	* nto-procfs.c: Use dirent.h.
	* procfs.c: Use dirent.h.

2013-11-18  Tom Tromey  <tromey@redhat.com>

	* config.in: Rebuild.
	* configure: Rebuild.
	* configure.ac: Don't use AC_HEADER_DIRENT.