bug408: delete

It's disabled and unreproducible.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/5642053

test/fixedbugs/bug408.go

-// true
-
-// WAS: errchk cgo $D/$F.go
-// but this fails (cgo succeeds) on OS X Snow Leopard
-// with Xcode 4.2 and gcc version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.1.00).
-
-// Copyright 2012 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.
-
-// Issue 1800: cgo not reporting line numbers.
-
-package main
-
-// #include <stdio.h>
-import "C"
-
-func f() {
-	C.printf(nil) // ERROR "go:15.*unexpected type"
-}