[Aboriginal] basic musl support is in.

[Rob Landley]

To enable it for a given target, comment out the UCLIBC_CONFIG stanza in
the sources/targets/$ARCH file.

All I can really say at the moment is that it compiles for i686. (That's
the ccwrap rewrite, basic script tweaks, and a patch to gcc to not use a
nonstandard type name.)

Sorry that took so long. It was a lot of debugging. (And now to test
build more stuff...)

Rob