add new bug: can't compile a, b := sys.frexp(1.0)

SVN=124622

test/bugs/bug056.go

+// $G $D/$F.go && $L $F.$A && ./$A.out
+
+// 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 main
+
+func frexp() (int, double) {
+	return 1, 2.0
+}
+
+func main() {
+	a, b := frexp();
+}
+
+/*
+bug056.go:8: illegal types for operand: AS
+	(<int32>INT32)
+	(<int32>INT32)
+*/

test/golden.out

@@ -263,6 +263,12 @@ BUG: known to fail incorrectly
 bug055.go:1: fatal error: cant open: bug055.go
 BUG: known to fail incorrectly
 
+=========== bugs/bug056.go
+bugs/bug056.go:9: illegal types for operand: AS
+	(<int32>INT32)
+	(<int32>INT32)
+BUG: compilation should succeed
+
 =========== fixedbugs/bug000.go
 
 =========== fixedbugs/bug001.go