Remove accessor properties not used by Fasta.

pkg/front_end/lib/src/fasta/kernel/body_builder.dart

Index: pkg/front_end/lib/src/fasta/kernel/body_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
index 258344083f6f9af9c13902181890308a3d8a739b..8d5af76f94e9ec17721c2db0c325a668d1f8c4d8 100644
--- a/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/body_builder.dart
@@ -2835,22 +2835,6 @@ abstract class ContextAccessor extends FastaAccessor {
 
   ContextAccessor(this.helper, this.token, this.accessor);
 
-  @override
-  Expression get builtBinary => internalError("Unsupported operation.");
-
-  @override
-  void set builtBinary(Expression expression) {
-    internalError("Unsupported operation.");
-  }
-
-  @override
-  Expression get builtGetter => internalError("Unsupported operation.");
-
-  @override
-  void set builtGetter(Expression expression) {
-    internalError("Unsupported operation.");
-  }
-
   String get plainNameForRead => internalError("Unsupported operation.");
 
   Expression doInvocation(int charOffset, Arguments arguments) {