dart2js: Distinguish precedence levels for left-hand side and call.

pkg/js_ast/lib/src/nodes.dart

Index: pkg/js_ast/lib/src/nodes.dart
diff --git a/pkg/js_ast/lib/src/nodes.dart b/pkg/js_ast/lib/src/nodes.dart
index 27511cafcdd83703620e470d87eccf8f1ce4cda1..94371a0e688c3ae61dcc7f8bd8fd7b314e02b575 100644
--- a/pkg/js_ast/lib/src/nodes.dart
+++ b/pkg/js_ast/lib/src/nodes.dart
@@ -904,7 +904,7 @@ class NamedFunction extends Expression {
   }
   NamedFunction _clone() => new NamedFunction(name, function);
 
-  int get precedenceLevel => CALL;
+  int get precedenceLevel => LEFT_HAND_SIDE;
 }
 
 class Fun extends Expression {
@@ -923,7 +923,7 @@ class Fun extends Expression {
 
   Fun _clone() => new Fun(params, body, asyncModifier: asyncModifier);
 
-  int get precedenceLevel => CALL;
+  int get precedenceLevel => LEFT_HAND_SIDE;
 }
 
 class AsyncModifier {
@@ -969,7 +969,7 @@ class PropertyAccess extends Expression {
 
   PropertyAccess _clone() => new PropertyAccess(receiver, selector);
 
-  int get precedenceLevel => CALL;
+  int get precedenceLevel => LEFT_HAND_SIDE;
 }
 
 /// A [DeferredToken] is a placeholder for some [Expression] that is not known