2014-05-09  Joey Ye  <joey.ye@arm.com>

	* files.c (find_file_in_dir): Always try to shorten for DOS
	non-system headers.
	* init.c (ENABLE_CANONICAL_SYSTEM_HEADERS): Default enabled for DOS.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@210264 138bc75d-0d04-0410-961f-82ee72b054a4