Unfortunately there's no simple, easy way to make Dial{TCP,UDP} fail
consistently across all platforms. Fow now we skip the test on Solaris.

Change-Id: Ib3c55f670ac6a174fe9ea682dac7aab96b1e9dfb
Reviewed-on: https://go-review.googlesource.com/11058Reviewed-by: Ian Lance Taylor <iant@golang.org>