testbed is now functional

I would like to make sure some _ tests are
passing, however I have to think of a nice
way to grab debug output and compare it
nicely.  Some require NReg == 3, that is a
pain in the ass.  Maybe they can be changed
to work for the full register set.

lisc/test/_rpo.ssa

@@ -0,0 +1,12 @@
+function $test() {
+@start
+	jmp @foo
+@baz
+	jnz 1, @end, @foo
+@bar
+	jmp @end
+@foo
+	jnz 0, @bar, @baz
+@end
+	ret
+}