make mklib work with cross compilation

make mklib work with cross compilation

The first hunk makes it use the compiler discovered by ./configure and thus
will work with cross compilers. Since Makefile.in exports CC and CXX, it seems
like mklib should be picking these up and not doing so is an upstream bug.

Then remove insertion of -m32, because this is not universally understood by
cross compilers. On Debian, the provided compiler will always choose the
correct ABI, so no -m32 or -m64 is necessary. This part likely is not
upstreamable.

Gbp-Pq: Name make-mklib-work-with-cross-compilation.patch