cppfiles.c (ENOTDIR): Remove.

	* cppfiles.c (ENOTDIR): Remove.
	(open_file_in_dir): Rename find_file_in_dir.  Handle errors
	other than ENOENT here.
	(once_only_file_p): Rename should_stack_file.
	(find_file, open_file_failed, read_file_guts): Report errors
	with full path name.
	(read_file): Move pch handling to should_stack_file.
	(should_stack_file): Handle PCH and once-only issues, and
	reading the file.
	(stack_file): Don't do file reads.

From-SVN: r70104