bug275: cannot apply real() to a complex array element

R=r, ken2
CC=golang-dev
https://golang.org/cl/1260041

test/bugs/bug275.go

+// $G $D/$F.go || echo BUG should compile
+
+// 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.
+
+// This is a test case for issue 788.
+
+package main
+
+func main() {
+	var a [1]complex64
+
+	t := a[0]
+	_ = real(t) // this works
+
+	_ = real(a[0]) // this doesn't
+}
+
+// bug275.go:17: internal compiler error: subnode not addable

test/golden.out

@@ -180,3 +180,7 @@ BUG: bug260 failed
 
 =========== bugs/bug274.go
 BUG: errchk: command succeeded unexpectedly
+
+=========== bugs/bug275.go
+bugs/bug275.go:17: internal compiler error: subnode not addable
+BUG should compile