Avoid unnecessary parsing/resolution when running command line analyzer.

pkg/analyzer/lib/src/generated/ast.dart

Index: pkg/analyzer/lib/src/generated/ast.dart
diff --git a/pkg/analyzer/lib/src/generated/ast.dart b/pkg/analyzer/lib/src/generated/ast.dart
index 277af7fb2983b6114e4d8f3f3fe5fdcce7ae2397..24d5068618e8da93fb8f419e7f8b1891354f2abd 100644
--- a/pkg/analyzer/lib/src/generated/ast.dart
+++ b/pkg/analyzer/lib/src/generated/ast.dart
@@ -11928,8 +11928,11 @@ class MethodDeclaration extends ClassMember {
   /**
    * Return `true` if this method is declared to be an abstract method.
    */
-  bool get isAbstract =>
-      externalKeyword == null && (_body is EmptyFunctionBody);
+  bool get isAbstract {
+    FunctionBody body = _body;
+    return externalKeyword == null &&
+        (body is EmptyFunctionBody && !body.semicolon.isSynthetic);
+  }
 
   /**
    * Return `true` if this method declares a getter.