code review 4290059: test: enable tests using v, ok := <-ch syntax

test/fixedbugs/bug196.go

 // $G $D/$F.go && $L $F.$A && ./$A.out || echo BUG: bug196
 
 // 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
 
 var m = map[int]int{0: 0, 1: 0}
 var nf = 0
 var i int
 
 func multi() (int, int) { return 1, 2 }
 
 func xxx() {
-        //TODO(rsc): uncomment when this syntax is valid for receive+check closed
-        //      var c chan int
-        //      x, ok := <-c
+        var c chan int
+        x, ok := <-c
 
         var m map[int]int
-        x, ok := m[1]
+        x, ok = m[1]
 
         var i interface{}
         var xx int
         xx, ok = i.(int)
 
         a, b := multi()
 
         _, _, _, _, _ = x, ok, xx, a, b
 }
 
@@ skipping 10 matching lines @@
 func main() {
         f()[0]++
         f()[1] += 2
         *g() %= 2
         if nf != 3 {
                 println("too many calls:", nf)
                 panic("fail")
         }
 
 }