misc/cgo: skip testso on ppc64

This test requires external linking, but we don't yet implement
external linking on ppc64 (tracked in issue #8912).  Disable the test
on ppc64 until external linking is implemented.

This makes all.bash pass on ppc64le.

Change-Id: I741498d4d9321607e7a65792a33faf8187bd18e4
Reviewed-on: https://go-review.googlesource.com/2908Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

misc/cgo/testso/test.bash

@@ -5,6 +5,12 @@
 
 set -e
 
+if [ "$(uname -m)" == ppc64 -o "$(uname -m)" == ppc64le ]; then
+	# External linking not implemented on ppc64
+	echo "skipping test on ppc64 (issue #8912)"
+	exit
+fi
+
 args=
 dyld_envvar=LD_LIBRARY_PATH
 ext=so