Add a test for a case where 6g thinks that a field is visible

when it should not be.  I couldn't get this any simpler; the
error seems to have to do with the order of the imports in
bug2.go.

R=rsc
DELTA=26  (26 added, 0 deleted, 0 changed)
OCL=23450
CL=23482

test/bugs/bug133.dir/bug0.go

+// 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.
+
+package bug0
+
+type T struct { i int }

test/bugs/bug133.dir/bug1.go

+// 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.
+
+package bug1
+
+import "bug0"
+
+type T struct { t bug0.T }

test/bugs/bug133.dir/bug2.go

+// 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.
+
+package bug1
+
+import "bug1"
+import "bug0"
+
+type T2 struct { t bug0.T }
+
+func fn(p *T2) int {
+	// This reference should be invalid, because bug0.T.i is local
+	// to package bug0 and should not be visible in package bug1.
+	return p.t.i
+}

test/bugs/bug133.go

+// $G $D/$F.dir/bug0.go && $G $D/$F.dir/bug1.go && errchk $G $D/$F.dir/bug2.go
+
+// 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.
+
+ignored

test/golden.out

@@ -181,6 +181,9 @@ BUG: should not compile
 =========== bugs/bug132.go
 BUG: compilation succeeds incorrectly
 
+=========== bugs/bug133.go
+BUG: succeeds incorrectly
+
 =========== fixedbugs/bug016.go
 fixedbugs/bug016.go:7: overflow converting constant to uint