Fix an error in the parser code to fix the dev build

R=danrubel@google.com

Review-Url: https://codereview.chromium.org/2821193002 .
diff --git a/pkg/analyzer/lib/src/generated/parser.dart b/pkg/analyzer/lib/src/generated/parser.dart
index e87b77b..18bb1c2 100644
--- a/pkg/analyzer/lib/src/generated/parser.dart
+++ b/pkg/analyzer/lib/src/generated/parser.dart
@@ -431,7 +431,7 @@
     }
     Token afterReturnType = skipTypeName(_currentToken);
     if (afterReturnType != null &&
-        _tokenMatchesKeyword(afterReturnType, Keyword.FUNCTION)) {
+        _tokenMatchesString(afterReturnType, 'Function')) {
       afterReturnType = skipGenericFunctionTypeAfterReturnType(afterReturnType);
     }
     if (afterReturnType == null) {
@@ -4174,7 +4174,7 @@
         return astFactory
             .emptyStatement(_createSyntheticToken(TokenType.SEMICOLON));
       }
-    } else if (_inGenerator && _matchesKeyword(Keyword.YIELD)) {
+    } else if (_inGenerator && _matchesString(_YIELD)) {
       return parseYieldStatement();
     } else if (_inAsync && _matchesString(_AWAIT)) {
       if (_tokenMatchesKeyword(_peek(), Keyword.FOR)) {
diff --git a/tools/VERSION b/tools/VERSION
index f52e40f..7427601 100644
--- a/tools/VERSION
+++ b/tools/VERSION
@@ -28,4 +28,4 @@
 MINOR 23
 PATCH 0
 PRERELEASE 11
-PRERELEASE_PATCH 8
+PRERELEASE_PATCH 9