More options files cleanup.

Change-Id: I12d067c8b3f52fe95026a642d83bb226405b5c45
Reviewed-on: https://dart-review.googlesource.com/c/81723
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Devon Carew <devoncarew@google.com>

pkg/compiler/analysis_options.yaml

@@ -3,8 +3,6 @@
 # BSD-style license that can be found in the LICENSE file.
 
 analyzer:
-  language:
-    enableSuperMixins: false
   errors:
     todo: ignore
     deprecated_member_use: ignore

pkg/dev_compiler/lib/src/analyzer/element_helpers.dart

@@ -10,7 +10,7 @@ import 'package:analyzer/src/generated/engine.dart' show AnalysisContext;
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart'
-    show DartType, InterfaceType, ParameterizedType, FunctionType;
+    show DartType, InterfaceType, FunctionType;
 import 'package:analyzer/src/dart/element/type.dart';
 import 'package:analyzer/src/generated/constant.dart'
     show DartObject, DartObjectImpl;

pkg/kernel/analysis_options.yaml

@@ -1,5 +1,3 @@
 analyzer:
-  language:
-    enableSuperMixins: false
   exclude:
     - testcases/**

pkg/testing/analysis_options.yaml

@@ -3,7 +3,6 @@
 # BSD-style license that can be found in the LICENSE file.
 
 analyzer:
-  strong-mode: true
   errors:
     # Allow having TODOs in the code
     todo: ignore

pkg/vm/analysis_options.yaml

@@ -3,9 +3,6 @@
 # BSD-style license that can be found in the LICENSE file.
 
 analyzer:
-  strong-mode: true
-  language:
-    enableSuperMixins: false
   exclude:
     - testcases/**
     - tool/**