more interface embedding tests 6g's error for I4 is not quite accurate (it calls I4 a non-interface) but also not a crash or infinite loop.
more interface embedding tests
6g's error for I4 is not quite accurate
(it calls I4 a non-interface) but also
not a crash or infinite loop.

R=iant
DELTA=15  (15 added, 0 deleted, 0 changed)
OCL=33701
CL=33709
abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go,abustany/go