Normalize on PATH_MAX instead of MAXPATHLEN throughout.

Normalize on PATH_MAX instead of MAXPATHLEN throughout.

With the pathmax gnulib module in place, we can use PATH_MAX
consistently throughout, instead of the current mixbag of PATH_MAX and
MAXPATHLEN uses.  It's no longer necessary to include sys/param.h
(supposedly, I can't check all ports touched here) for MAXPATHLEN.

Don't remove sys/param.h from GDB's configure.ac, as later tests in
the file use HAVE_SYS_PARAM_H checks.

Tested on x86_64 Fedora 17.

Also cross-built for --host=i686-w64-mingw32, and --host=i586-pc-msdosdjgpp.

gdb/
2013-07-01  Pedro Alves  <palves@redhat.com>

	* defs.h: Include "pathmax.h".
	* utils.c: Don't include sys/param.h.
	(gdb_realpath): Remove code that checks for MAXPATHLEN.
	* solib-ia64-hpux.c (ia64_hpux_handle_load_event): Use PATH_MAX
	instead of MAXPATHLEN.
	* solib-sunos.c: Don't include sys/param.h.
	* xcoffread.c: Don't include sys/param.h.
	* bsd-kvm.c: Don't include sys/param.h.
	* darwin-nat.c: Don't include sys/param.h.
	(darwin_pid_to_exec_file): Use PATH_MAX instead of MAXPATHLEN.
	* darwin-nat-info.c: Don't include sys/param.h.
	* fbsd-nat.c (fbsd_pid_to_exec_file): Use PATH_MAX instead of
	MAXPATHLEN.
	* i386obsd-nat.c: Don't include sys/param.h.
	* inf-child.c: Don't include sys/param.h.
	(inf_child_fileio_readlink): Use PATH_MAX instead of MAXPATHLEN.
	* linux-fork.c: Don't include sys/param.h.
	(fork_save_infrun_state): Use PATH_MAX instead of MAXPATHLEN.
	* linux-nat.c: Don't include sys/param.h.
	(linux_child_pid_to_exec_file, linux_proc_pending_signals)
	(linux_proc_pending_signals): Use PATH_MAX instead of MAXPATHLEN.
	* m68klinux-nat.c: Don't include sys/param.h.
	* nbsd-nat.c: Don't include sys/param.h.
	(nbsd_pid_to_exec_file): Use PATH_MAX instead of MAXPATHLEN.
	* ppc-linux-nat.c: Don't include sys/param.h.
	* rs6000-nat.c: Don't include sys/param.h.
	* spu-linux-nat.c. Don't include sys/param.h.
	* windows-nat.c: Don't include sys/param.h.
	* xtensa-linux-nat.c: Don't include sys/param.h.
	* config/i386/nm-fbsd.h: Don't include sys/param.h.

gdb/gdbserver/
2013-07-01  Pedro Alves  <palves@redhat.com>

	* server.h: Include "pathmax.h".
	* linux-low.c: Don't include sys/param.h.
	(linux_pid_exe_is_elf_64_file): Use PATH_MAX instead of
	MAXPATHLEN.
	* win32-low.c: Don't include sys/param.h.
	(win32_create_inferior): Use PATH_MAX instead of MAXPATHLEN.