Some cgo tests aren't yet available on aix/ppc64.
-shared and -static don't work as expected and will be fixed latter.

Updates #30565

Change-Id: Ic59cabe685cb1cbdf89a8d1d1a1d2c4b0e8ef442
Reviewed-on: https://go-review.googlesource.com/c/go/+/164018
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>