code review 10271046: cmd/gc: fix computation of equality class of types.

test/cmp.go

 // run
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 // Test equality and inequality operations.
 
 package main
 
@@ skipping 278 matching lines @@
                 istrue(iy != z)
                 istrue(iz != y)
                 isfalse(ix != z)
                 isfalse(iz != x)
         }
 
         // structs with _ fields
         {
                 var x = struct {
                         x int
-                        _ []int
+                        _ string
                         y float64
                         _ float64
                         z int
                 }{
                         x: 1, y: 2, z: 3,
                 }
                 var ix interface{} = x
 
                 istrue(x == x)
                 istrue(x == ix)
@@ skipping 110 matching lines @@
 }
 
 func shouldPanic(f func()) {
         defer func() {
                 if recover() == nil {
                         panic("function should panic")
                 }
         }()
         f()
 }