Fix increment on nullable

test/codegen/expect/dart/async.js

 var async;
 (function(exports) {
   'use strict';
   dart.copyProperties(exports, {
     get _hasDocument() {
       return dart.equals(typeof document, 'object');
     }
   });
   // Function _invokeErrorHandler: (Function, Object, StackTrace) → dynamic
   function _invokeErrorHandler(errorHandler, error, stackTrace) {
@@ skipping 475 matching lines @@
         this[_pauseCount] = 0;
       }
       onData(handleData) {}
       onError(handleError) {}
       onDone(handleDone) {}
       pause(resumeSignal) {
         if (resumeSignal === void 0)
           resumeSignal = null;
         if (resumeSignal !== null)
           resumeSignal.then(this[_resume]);
-        dart.notNull(this[_pauseCount])++;
+        this[_pauseCount] = dart.notNull(this[_pauseCount]) + 1;
       }
       resume() {
         this[_resume](null);
       }
       [_resume](_) {
         if (dart.notNull(this[_pauseCount]) > 0)
-          dart.notNull(this[_pauseCount])--;
+          this[_pauseCount] = dart.notNull(this[_pauseCount]) - 1;
       }
       cancel() {
         return new _Future.immediate(null);
       }
       get isPaused() {
         return dart.notNull(this[_pauseCount]) > 0;
       }
       asFuture(value) {
         if (value === void 0)
           value = null;
@@ skipping 97 matching lines @@
       static wait(futures, opt$) {
         let eagerError = opt$.eagerError === void 0 ? false : opt$.eagerError;
         let cleanUp = opt$.cleanUp === void 0 ? null : opt$.cleanUp;
         let result = new _Future();
         let values = null;
         let remaining = 0;
         let error = null;
         let stackTrace = null;
         // Function handleError: (dynamic, dynamic) → void
         function handleError(theError, theStackTrace) {
-          dart.notNull(remaining)--;
+          remaining = dart.notNull(remaining) - 1;
           if (values !== null) {
             if (cleanUp !== null) {
               for (let value of values) {
                 if (value !== null) {
                   new Future.sync(() => {
                     cleanUp(value);
                   });
                 }
               }
             }
             values = null;
             if (remaining === 0 || dart.notNull(eagerError)) {
               result._completeError(theError, dart.as(theStackTrace, core.StackTrace));
             } else {
               error = theError;
               stackTrace = dart.as(theStackTrace, core.StackTrace);
             }
           } else if (remaining === 0 && !dart.notNull(eagerError)) {
             result._completeError(error, stackTrace);
           }
         }
         for (let future of futures) {
-          let pos = dart.notNull(remaining)++;
+          let pos = (($tmp) => remaining = dart.notNull($tmp) + 1, $tmp)(remaining);
           future.then(dart.as(((value) => {
-            dart.notNull(remaining)--;
+            remaining = dart.notNull(remaining) - 1;
             if (values !== null) {
               values.set(pos, value);
               if (remaining === 0) {
                 result._completeWithValue(values);
               }
             } else {
               if (dart.notNull(cleanUp !== null) && dart.notNull(value !== null)) {
                 new Future.sync(() => {
                   cleanUp(value);
                 });
@@ skipping 831 matching lines @@
           computation = null;
         if (computation === null)
           computation = (i) => null;
         let timer = null;
         let computationCount = 0;
         let controller = null;
         let watch = new core.Stopwatch();
         // Function sendEvent: () → void
         function sendEvent() {
           watch.reset();
-          let data = computation(dart.notNull(computationCount)++);
+          let data = computation((($tmp) => computationCount = dart.notNull($tmp) + 1, $tmp)(computationCount));
           controller.add(data);
         }
         // Function startPeriodicTimer: () → void
         function startPeriodicTimer() {
           dart.assert(timer === null);
           timer = new Timer.periodic(period, (timer) => {
             sendEvent();
           });
         }
         controller = new StreamController({sync: true, onListen: (() => {
@@ skipping 249 matching lines @@
           }, dart.throw_("Unimplemented type (dynamic) → dynamic")), dart.as(_cancelAndErrorClosure(subscription, future), dart.throw_("Unimplemented type (dynamic, StackTrace) → dynamic")));
         }, {onError: future[_completeError], onDone: (() => {
             future._complete(false);
           }).bind(this), cancelOnError: true});
         return future;
       }
       get length() {
         let future = new _Future();
         let count = 0;
         this.listen((_) => {
-          dart.notNull(count)++;
+          count = dart.notNull(count) + 1;
         }, {onError: future[_completeError], onDone: (() => {
             future._complete(count);
           }).bind(this), cancelOnError: true});
         return future;
       }
       get isEmpty() {
         let future = new _Future();
         let subscription = null;
         subscription = this.listen((_) => {
           _cancelAndValue(subscription, future, false);
@@ skipping 2036 matching lines @@
   let _SkipStream$ = dart.generic(function(T) {
     class _SkipStream extends _ForwardingStream$(T, T) {
       _SkipStream(source, count) {
         this[_remaining] = count;
         super._ForwardingStream(source);
         if (dart.notNull(!(typeof count == number)) || dart.notNull(count) < 0)
           throw new core.ArgumentError(count);
       }
       [_handleData](inputEvent, sink) {
         if (dart.notNull(this[_remaining]) > 0) {
-          dart.notNull(this[_remaining])--;
+          this[_remaining] = dart.notNull(this[_remaining]) - 1;
           return;
         }
         sink._add(inputEvent);
       }
     }
     return _SkipStream;
   });
   let _SkipStream = _SkipStream$(dynamic);
   let _hasFailed = Symbol('_hasFailed');
   let _SkipWhileStream$ = dart.generic(function(T) {
@@ skipping 1107 matching lines @@
   exports.StreamIterator$ = StreamIterator$;
   exports.StreamController = StreamController;
   exports.StreamController$ = StreamController$;
   exports.Timer = Timer;
   exports.AsyncError = AsyncError;
   exports.ZoneSpecification = ZoneSpecification;
   exports.ZoneDelegate = ZoneDelegate;
   exports.Zone = Zone;
   exports.runZoned = runZoned;
 })(async || (async = {}));