configure.in: Add check for lstat.

	* configure.in: Add check for lstat.
	* configure, config.in: Regenerate.
	* cppinit.c (append_include_chain): Make empty path ".".
        * cpplib.c (do_line): Don't simplify #line paths.
        * cppfiles.c (remove_component_p): New function.
	(find_or_create_entry): Acknowledge stat () errors during
	path simplification.
	(handle_missing_header): Don't simplify paths.
        (_cpp_simplify_pathname): Don't simplify VMS paths.  Return
        the empty path untouched.  Don't leave a trailing '/'.

From-SVN: r41148