gc: import dot shadowing bug

R=ken2
CC=golang-dev
https://golang.org/cl/1873047

src/cmd/gc/typecheck.c

@@ -1781,6 +1781,11 @@ typecheckcomplit(Node **np)
 					typecheck(&l->right, Erv);
 					continue;
 				}
+				// Sym might have resolved to name in other top-level
+				// package, because of import dot.  Redirect to correct sym
+				// before we do the lookup.
+				if(s->pkg != localpkg)
+					s = lookup(s->name);
 				l->left = newname(s);
 				l->left->typecheck = 1;
 				f = lookdot1(s, t, t->type, 0);

test/fixedbugs/bug295.go

@@ -0,0 +1,17 @@
+// $G $D/$F.go && $L $F.$A && ./$A.out
+
+// Copyright 2010 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 main
+
+import . "testing"  // defines top-level T
+
+type S struct {
+	T int
+}
+
+func main() {
+	_ = &S{T: 1}	// should work
+}