Remove harmony-atomics flag and collapse it into sharedarraybuffer flag

test/mjsunit/asm/atomics-compareexchange.js

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --harmony-atomics --harmony-sharedarraybuffer
+// Flags: --harmony-sharedarraybuffer
 
 function Module(stdlib, foreign, heap) {
   "use asm";
   var MEM8 = new stdlib.Int8Array(heap);
   var MEM16 = new stdlib.Int16Array(heap);
   var MEM32 = new stdlib.Int32Array(heap);
   var MEMU8 = new stdlib.Uint8Array(heap);
   var MEMU16 = new stdlib.Uint16Array(heap);
   var MEMU32 = new stdlib.Uint32Array(heap);
   var MEMF32 = new stdlib.Float32Array(heap);
@@ skipping 96 matching lines @@
 }
 
 testElementType(Int8Array, m.compareExchangei8, 0);
 testElementType(Int16Array, m.compareExchangei16, 0);
 testElementType(Int32Array, m.compareExchangei32, 0);
 testElementType(Uint8Array, m.compareExchangeu8, 0);
 testElementType(Uint16Array, m.compareExchangeu16, 0);
 testElementType(Uint32Array, m.compareExchangeu32, 0);
 testElementType(Float32Array, m.compareExchangef32, NaN);
 testElementType(Float64Array, m.compareExchangef64, NaN);