bmake fails to build those targets in src/lib/libc/arch/mips,
because there are explicit rules in the Makefiles that
depend on .S targets, not .s.  This is with NetBSD-current.

I don't understand bmake well enough to know if there's some clean way
to change the suffixes using some macro. And it looks like the
libc/arc/mips files want to go through a preprocessor before going to
an as built from gas (as opposed to the MIPSco, now SGI, /bin/as in
ultrix).

So, given gcc's conventions about invoking a preprocessor on
assembly-code, I think the right long-term fix is to rename all those
files from <foo>.s to <foo.>.S

For now I'm making symlinks...

------------------------------------------------------------------------------