A step towards handling `new Object()` in compile_from_dill_test

pkg/compiler/lib/src/kernel/element_map_impl.dart

 // Copyright (c) 2017, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library dart2js.kernel.element_map;
 
 import 'package:kernel/ast.dart' as ir;
 import 'package:kernel/clone.dart';
 import 'package:kernel/type_algebra.dart';
 
@@ skipping 462 matching lines @@
                   _getTypeVariable(node.typeParameters[index]));
             }));
         env.rawType = new InterfaceType(
             cls,
             new List/*<DartType>*/ .filled(
                 node.typeParameters.length, const DynamicType()));
       }
     }
   }
 
-  InterfaceType _getThisType(KClass cls) {
+  InterfaceType getThisType(KClass cls) {
     _KClassEnv env = _classEnvs[cls.classIndex];
     _ensureThisAndRawType(cls, env);
     return env.thisType;
   }
 
   InterfaceType _getRawType(KClass cls) {
     _KClassEnv env = _classEnvs[cls.classIndex];
     _ensureThisAndRawType(cls, env);
     return env.rawType;
   }
@@ skipping 57 matching lines @@
   }
 
   ClassEntity _getAppliedMixin(KClass cls) {
     _KClassEnv env = _classEnvs[cls.classIndex];
     _ensureSupertypes(cls, env);
     return env.mixedInType?.element;
   }
 
   DartType _substByContext(DartType type, InterfaceType context) {
     return type.subst(
-        context.typeArguments, _getThisType(context.element).typeArguments);
+        context.typeArguments, getThisType(context.element).typeArguments);
   }
 
   InterfaceType _getSuperType(KClass cls) {
     _KClassEnv env = _classEnvs[cls.classIndex];
     _ensureSupertypes(cls, env);
     return env.supertype;
   }
 
   bool _isUnnamedMixinApplication(KClass cls) {
     _KClassEnv env = _classEnvs[cls.classIndex];
@@ skipping 529 matching lines @@
   LibraryEntity get mainLibrary => elementMap._mainLibrary;
 
   @override
   FunctionEntity get mainFunction => elementMap._mainFunction;
 
   @override
   Iterable<LibraryEntity> get libraries => elementMap._libraries;
 
   @override
   InterfaceType getThisType(ClassEntity cls) {
-    return elementMap._getThisType(cls);
+    return elementMap.getThisType(cls);
   }
 
   @override
   InterfaceType getRawType(ClassEntity cls) {
     return elementMap._getRawType(cls);
   }
 
   @override
   bool isGenericClass(ClassEntity cls) {
     return getThisType(cls).typeArguments.isNotEmpty;
@@ skipping 431 matching lines @@
     return node.isExternal &&
         !elementMap.isForeignLibrary(node.enclosingLibrary);
   }
 
   @override
   bool isJsInteropMember(MemberEntity element) {
     // TODO(johnniwinther): Compute this.
     return false;
   }
 }