doc/go1.3.html: gccgo status

LGTM=iant
R=iant
CC=golang-codereviews
https://golang.org/cl/85720043

doc/go1.3.html

@@ -106,7 +106,10 @@ effect on programs.
 <h3 id="gccgo">Status of gccgo</h3>
 
 <p>
-TODO
+GCC release 4.9 will contain the Go 1.2 (not 1.3) version of gccgo.
+The release schedules for the GCC and Go projects do not coincide,
+which means that 1.3 will be available in the development branch but
+that the next GCC release, 4.10, will likely have the Go 1.4 version of gccgo.
 </p>
 
 <h3 id="gocmd">Changes to the go command</h3>