Improve Executable displayed path (PR 15415 regression kind #2)

Improve Executable displayed path (PR 15415 regression kind #2)

gdb/
2013-10-13  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Canonicalize directories for EXEC_FILENAME.
	* exec.c (exec_file_attach): Use gdb_realpath_keepfile for
	exec_filename.
	* utils.c (gdb_realpath_keepfile): New function.
	* utils.h (gdb_realpath_keepfile): New declaration.

gdb/testsuite/
2013-10-13  Jan Kratochvil  <jan.kratochvil@redhat.com>

	Canonicalize directories for EXEC_FILENAME.
	* gdb.base/argv0-symlink.exp
	(kept file symbolic link name for info inferiors): New.
	(kept directory symbolic link name): Setup kfail.
	(kept directory symbolic link name for info inferiors): New.