The compiler should reject calling a const as though it were a

function.  Also update golden.out.

R=r
DELTA=18  (18 added, 0 deleted, 0 changed)
OCL=19433
CL=19448

test/bugs/bug123.go

+// errchk $G $D/$F.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 main
+const ( F = 1 )
+func fn(i int) int {
+  if i == F() {		// ERROR "function"
+    return 0
+  }
+  return 1
+}

test/golden.out

@@ -157,6 +157,15 @@ Bad float64 const: 1e23+1 want 1.0000000000000001e+23 got 1e+23
 	want exact: 100000000000000008388608
 	got exact:  99999999999999991611392
 
+=========== bugs/bug121.go
+BUG: compilation succeeds incorrectly
+
+=========== bugs/bug122.go
+BUG: compilation succeeds incorrectly
+
+=========== bugs/bug123.go
+BUG: errchk: command succeeded unexpectedly:  6g bugs/bug123.go
+
 =========== fixedbugs/bug016.go
 fixedbugs/bug016.go:7: overflow converting constant to uint