feature request: a job that attempts cross-compilation of a package

anybody thought about adding a cross-building job?

i usually apply all the patches that @helmutg submits, to allow cross-compilation of my packages. however, i'm pretty sure that sometimes an upgrade of the package breaks cross-compilability.

so i would like to suggest a job, that attempts to cross-compile.

probably @helmutg could provide some insights what is actually needed. i assume something like:

• build host is amd64
• target arch is one of the release architectures (but probably not i386)
• the job probably should have allow_failure set by default