Work around for private names in mixin applications.

test/kernel/regression/issue_000081.dart.txt

Index: test/kernel/regression/issue_000081.dart.txt
diff --git a/test/kernel/regression/issue_000081.dart.txt b/test/kernel/regression/issue_000081.dart.txt
index 6079605763e199773b7c9c1b15307338eb3e0ac8..a569e153ce67a8ebb722b5b32e55c24d4334477a 100644
--- a/test/kernel/regression/issue_000081.dart.txt
+++ b/test/kernel/regression/issue_000081.dart.txt
@@ -8,13 +8,13 @@ class Base extends core::Object {
     : self::Base::hashCode = 42, super core::Object::•();
 }
 class Sub extends self::Base {
-  field core::int _hashCode;
+  field core::int _hashCode@issue_000081.dart;
   constructor •() → self::Sub
-    : self::Sub::_hashCode = null, super self::Base::•();
+    : self::Sub::_hashCode@issue_000081.dart = null, super self::Base::•();
   get hashCode() → dynamic
-    return let final dynamic #t1 = this._hashCode in #t1.==(null) ? this._hashCode = super.self::Base::hashCode : #t1;
+    return let final dynamic #t1 = this._hashCode@issue_000081.dart in #t1.==(null) ? this._hashCode@issue_000081.dart = super.self::Base::hashCode : #t1;
   method foo() → dynamic {
-    this._hashCode.==(null) ? this._hashCode = super.self::Base::hashCode : null;
+    this._hashCode@issue_000081.dart.==(null) ? this._hashCode@issue_000081.dart = super.self::Base::hashCode : null;
   }
 }
 static method main() → dynamic {