Port parser and scanner fixes from rasta branch.

pkg/dart_scanner/lib/src/keyword.dart

Index: pkg/dart_scanner/lib/src/keyword.dart
diff --git a/pkg/dart_scanner/lib/src/keyword.dart b/pkg/dart_scanner/lib/src/keyword.dart
index c40c636b23066e33b9919ab2429d713f04a899f3..2a5bf64f5adb51003e935eaf96d7e3f33527a836 100644
--- a/pkg/dart_scanner/lib/src/keyword.dart
+++ b/pkg/dart_scanner/lib/src/keyword.dart
@@ -74,16 +74,17 @@ class Keyword {
     const Keyword("static", isBuiltIn: true),
     const Keyword("typedef", isBuiltIn: true),
 
+    const Keyword("async", isPseudo: true),
+    const Keyword("await", isPseudo: true),
+    const Keyword("deferred", isPseudo: true),
     const Keyword("hide", isPseudo: true),
     const Keyword("native", isPseudo: true),
     const Keyword("of", isPseudo: true),
     const Keyword("on", isPseudo: true),
+    const Keyword("patch", isPseudo: true),
     const Keyword("show", isPseudo: true),
     const Keyword("source", isPseudo: true),
-    const Keyword("deferred", isPseudo: true),
-    const Keyword("async", isPseudo: true),
     const Keyword("sync", isPseudo: true),
-    const Keyword("await", isPseudo: true),
     const Keyword("yield", isPseudo: true),
   ];