Temporarily apply a patch from upstream that addresses a build failure
on powerpc ("error: integer constant is too large for 'long' type").

This is already part of lang/gcc9-devel after r518494 and the 20191123
snapshot of GCC 9.2.1; it will be part of the GCC 9.3 release at which
point we can remove this local patch again.

PR: 241125