allow await to be any value, fixes part of #264

Review URL: https://codereview.chromium.org/1248213002 .

Author: John Messerly

pkg/dev_compiler/lib/src/checker/checker.dart

@@ -669,12 +669,6 @@ class CodeChecker extends RecursiveAstVisitor {
     node.visitChildren(this);
   }
 
-  @override
-  void visitAwaitExpression(AwaitExpression node) {
-    checkAssignment(node.expression, rules.provider.futureDynamicType);
-    node.visitChildren(this);
-  }
-
   @override
   void visitPropertyAccess(PropertyAccess node) {
     var target = node.realTarget;

pkg/dev_compiler/pubspec.yaml

@@ -1,5 +1,5 @@
 name: dev_compiler
-version: 0.1.2
+version: 0.1.3
 description: >
   Experimental Dart to JavaScript compiler designed to create idiomatic,
   readable JavaScript output.

pkg/dev_compiler/test/checker/checker_test.dart

@@ -2692,11 +2692,16 @@ void main() {
         Future<int> z;
 
         void baz() async {
-          int a = /*info:DynamicCast*/await /*info:DynamicCast*/x;
-          int b = await /*severe:StaticTypeError*/y;
+          int a = /*info:DynamicCast*/await x;
+          int b = await y;
           int c = await z;
           String d = /*severe:StaticTypeError*/await z;
         }
+
+        Future<bool> get issue_264 async {
+          await 42;
+          return false;
+        }
     '''
     }));