gdb/

gdb/
	* symfile.c (build_id_to_debug_filename): New variable debugdir.  Move
	variables size, s and data into a new inner block.  Change xmalloc for
	alloca, use direct BUILDID->SIZE there now.  Loop for the
	DEBUG_FILE_DIRECTORY components.
	(find_separate_debug_file): New variable debugdir and debugdir_end.
	Loop for the DEBUG_FILE_DIRECTORY components.
	(_initialize_symfile): For "debug-file-directory" use plural and note
	one can use multiple components now.

gdb/doc/
	* gdb.texinfo (set debug-file-directory, show debug-file-directory)
	(Auto-loading): Use plural and note one can use multiple components now.

gdb/testsuite/
	* gdb.base/sepdebug.exp: New test_different_dir call for multiple-dirs.