It doesn't build yet when cross-compiling, though. It needs REGLIB,
SALLIB and SALHELPERLIB, and so far these get built only for the host
platform when cross-compiling.

Need to fix that. Can't have this ad-hoc mixing of build platform
tools and host platform libs in the same OUTDIR any more. When
cross-compiling we should do a full separation of binaries for build
and host. Libraries like SALLIB are needed for both.