Changes

drop loong64 patch #1031850 resolved in gcc-13

adapt to linux-libc-dev having become a:all+m-a:foreign

Most of the time, we no longer have to rebuild linux-libc-dev.
Sometimes, it's missing headers though and then we need to rebuild it,
but not as a cross build, but an indep-only build.

linux: circumvent control generation protection more reliably

reenable building of gcc-13 common libraries

gcc-14 entered unstable.

adapt linux patching to toml based configuration

rewrite wdotap patch set on top of gcc-for-host changes

The merging of gcc-for-host caused a lot of changes to the gcc packaging
and made the wdotap patch set from cross-gcc-dev no longer work. It
required significant changes and quite some aspects could be dropped
resulting in a much smaller patch that is inlined in rebootstrap for
now. We'll see whether that works better or worse.

don't attempt to install linux-libc-dev with an :arch qualifier