test: use testlib in a few more cases

        Introduce a new skip cmd.

R=golang-dev, bradfitz, iant, iant
CC=golang-dev
https://golang.org/cl/5868048

test/cmplxdivide.c

@@ -51,6 +51,7 @@ main(void)
 	int i, j, k, l;
 	double complex n, d, q;
 	
+	printf("// skip\n");
 	printf("// # generated by cmplxdivide.c\n");
 	printf("\n");
 	printf("package main\n");

test/cmplxdivide1.go

+// skip
 // # generated by cmplxdivide.c
 
 package main

test/ddd2.go

-// true
+// skip
 
 // Copyright 2010 The Go Authors.  All rights reserved.
 // Use of this source code is governed by a BSD-style

test/fixedbugs/bug223.go

-// (! $G $D/$F.go) | grep 'initialization loop' >/dev/null || echo BUG: bug223
+// errorcheck
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
@@ -18,4 +18,4 @@ func f() {
 	}
 }
 
-var m = map[string]F{"f": f}
+var m = map[string]F{"f": f} // ERROR "initialization loop"

test/import2.go

-// true  # used by import3
+// skip # used by import3
 
 // Copyright 2010 The Go Authors.  All rights reserved.
 // Use of this source code is governed by a BSD-style

test/interface/embed0.go

-// true	# used by embed1.go
+// skip # used by embed1.go
 
 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

test/interface/private1.go

-// true  # used by private.go
+// skip # used by private.go
 
 // Copyright 2011 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

test/interface/recursive1.go

-// true  # used by recursive2
+// skip # used by recursive2
 
 // Copyright 2012 The Go Authors.  All rights reserved.
 // Use of this source code is governed by a BSD-style

test/method4a.go

-// true
+// skip
 
 // Copyright 2012 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style

test/run.go

-// #ignore
+// skip
 
 // Copyright 2012 The Go Authors.  All rights reserved.
 // Use of this source code is governed by a BSD-style
@@ -172,7 +172,7 @@ type test struct {
 	donec       chan bool // closed when done
 
 	src    string
-	action string // "compile", "build", "run", "errorcheck"
+	action string // "compile", "build", "run", "errorcheck", "skip"
 
 	tempDir string
 	err     error
@@ -253,6 +253,9 @@ func (t *test) run() {
 		fallthrough
 	case "compile", "build", "run", "errorcheck":
 		t.action = action
+	case "skip":
+		t.action = "skip"
+		return
 	default:
 		t.err = skipError("skipped; unknown pattern: " + action)
 		t.action = "??"

test/testlib

@@ -38,3 +38,7 @@ cmpout() {
 errorcheck() {
 	errchk $G -e $D/$F.go
 }
+
+skip() {
+	true
+}