[build] Support libgo on Solaris 2

[Ian Lance Taylor]

> From: Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE>
> Date: Mon, 10 Jan 2011 16:23:05 +0100

> FAIL: go.test/test/chan/powser2.go execution,  -O2 -g 

> FAIL: go.test/test/chan/powser2.go execution,  -O2 -g 

> The test fails with
>
> panic: runtime error: invalid memory address or nil pointer dereference
>
> I haven't yet investigated what's up there.

This is most likely the lack of split stack support.  The test is
probably overrunning the stack.

Ian