This series improves the checking of --with-arch, --with-cpu and --with-tune options in config.gcc.
Patch 1/2 fixes a rejects-valid bug for hyphenated extension names. Patch 2/2 improves the checks to reject more (all?) invalid values, and prevents an infinite loop. Is this ok for master? I'd also like to backport at least patch 1/2 to all open branches. Thanks, Alice
