Fix cross building.
Fix cross building.

When we stopped using CXXFLAGS in eh_personality.s generation, we lost
the ability to propagate -m32 or -target through, so cross-compile
didn't work.  These flags are now passed through correctly, so (so
'-pipe -O2' will appear as two arguments, rather than being combined as
a single value that then causes clang to abort with an unknown argument
error, which was the original motivation for this change).

This is the correct fix for #177

gnustep/libobjc2,gnustep/libobjc2