Bug#947235: port patches to gcc-10

[Dima Kogan]

I just uploaded cross-gcc-dev=241. A patch stack for gcc-10 is included.
The patches apply (they come from a git tree, as all the other patch
stacks). I have not actually attempted to build a compiler using these
patches, and clearly I have not tested the output from such compiler.
Please let me know if something doesn't work.