re PR preprocessor/15933 (Caching of include files breaks compilation)

	PR 15933
	Partially revert patch of 2004-06-05.
	* files.c (search_cache): Remove pfile argument.  Don't check
	for file that would be found by "" or <> search here...
	(_cpp_find_file): ...do it here, before calling find_file_in_dir.
	Do not apply directory-of-current-file correction to files
	found by this check.  Rearrange code slightly.

From-SVN: r83714