Patches should go to gcc-patches.
Just a trivial remark:
> --- gcc/c-family/c-opts.c (revision 250514)
> +++ gcc/c-family/c-opts.c (working copy)
> @@ -1152,8 +1152,11 @@
> FILE *deps_stream = NULL;
> - /* Don't write the deps file if there are errors. */
> - if (cpp_opts->deps.style != DEPS_NONE && !seen_error ())
> + /* Note that we write the dependencies even if there are errors. This is
> + useful for handling outdated generated headers that now trigger errors
> + (for example, with #error) that would be resolved by re-generating
> + them. In a sense this complements -MG. */
Two spaces after a full stop (all three times).