doc: tweak Solaris wording

Suggested in comments on CL 85740043.

LGTM=aram
R=golang-codereviews, aram
CC=dave, golang-codereviews, r
https://golang.org/cl/85990044

doc/go1.3.html

@@ -39,8 +39,7 @@ how to set up the Go version is described <a href="http://golang.org/wiki/Native
 <h3 id="solaris">Support for Solaris</h3>
 
 <p>
-Go 1.3 now includes preliminary support for Solaris on the <code>amd64</code> (64-bit x86) architecture.
-The Solaris port of Go is not ready for production use and must be built from source.
+Go 1.3 now includes experimental support for Solaris on the <code>amd64</code> (64-bit x86) architecture.
 </p>