test: add new test of indirect type references

Similar to bug190, but without recursive reference.  Crashed
gccgo.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5672053

test/fixedbugs/bug417.go

+// $G $D/$F.go || echo BUG: should compile
+
+// 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.
+
+// Some indirect uses of types crashed gccgo, because it assumed that
+// the size of the type was known before it had been computed.
+
+package p
+
+type S1 struct {
+	p *[1]S3
+	s [][1]S3
+	m map[int][1]S3
+	c chan [1]S3
+	i interface { f([1]S3) [1]S3 }
+	f func([1]S3) [1]S3
+}
+
+type S2 struct {
+	p *struct { F S3 }
+	s []struct { F S3 }
+	m map[int]struct { F S3 }
+	c chan struct { F S3 }
+	i interface { f(struct { F S3 }) struct { F S3 } }
+	f func(struct { F S3 } ) struct { F S3 }
+}
+
+type S3 struct {
+	I int
+}