runtime: add go:noescape declaration for Solaris

    
    Patch by Rainer Orth.
    
    Reviewed-on: https://go-review.googlesource.com/88376

From-SVN: r256872

gcc/go/gofrontend/MERGE

-925635f067d40d30acf565b620cc859ee7cbc990
+6b4f1391e2cd637fa5ed797bb3ab43d9ede61997
 
 The first line of this file holds the git revision number of the last
 merge done from the gofrontend repository.

libgo/go/runtime/netpoll_solaris.go

@@ -84,6 +84,7 @@ func port_associate(port, source int32, object uintptr, events uint32, user uint
 //extern port_dissociate
 func port_dissociate(port, source int32, object uintptr) int32
 
+//go:noescape
 //extern port_getn
 func port_getn(port int32, evs *portevent, max uint32, nget *uint32, timeout *timespec) int32