Clean up TODOs in TryConstantEvaluator.

Issue: #48820
Change-Id: I01a9c7b1de3697afc2d643a5a1c7aaa26532ea70
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/352974
Commit-Queue: Mayank Patke <fishythefish@google.com>
Reviewed-by: Johnni Winther <johnniwinther@google.com>

pkg/compiler/lib/src/ir/constants.dart

@@ -15,7 +15,7 @@ class Dart2jsConstantEvaluator extends ir.TryConstantEvaluator {
       ir.TypeEnvironment typeEnvironment, ir.ReportErrorFunction reportError,
       {Environment? environment,
       super.supportReevaluationForTesting,
-      super.evaluationMode})
+      required super.evaluationMode})
       : super(
           const Dart2jsDartLibrarySupport(),
           const Dart2jsConstantsBackend(supportsUnevaluatedConstants: false),

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

@@ -24,7 +24,7 @@ class ConstConditionalSimplifier extends RemovingTransformer {
     this._component,
     ReportErrorFunction _reportError, {
     Map<String, String>? environmentDefines,
-    EvaluationMode evaluationMode = EvaluationMode.weak,
+    required EvaluationMode evaluationMode,
     bool Function(TreeNode)? shouldNotInline,
     CoreTypes? coreTypes,
     ClassHierarchy? classHierarchy,
@@ -122,7 +122,7 @@ class _ConstantEvaluator extends TryConstantEvaluator {
   _ConstantEvaluator(super.librarySupport, super.constantsBackend,
       super.component, super.typeEnvironment, super.reportError,
       {super.environmentDefines,
-      super.evaluationMode,
+      required super.evaluationMode,
       bool Function(TreeNode)? shouldNotInline})
       : _shouldNotInline = shouldNotInline ?? ((_) => false);
 

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

@@ -15,6 +15,9 @@ typedef ReportErrorFunction = void Function(
 class TryConstantEvaluator extends ConstantEvaluator {
   final bool _supportReevaluationForTesting;
 
+  @override
+  final _ErrorReporter errorReporter;
+
   TryConstantEvaluator(
       DartLibrarySupport librarySupport,
       ConstantsBackend constantsBackend,
@@ -22,28 +25,28 @@ class TryConstantEvaluator extends ConstantEvaluator {
       TypeEnvironment typeEnvironment,
       ReportErrorFunction reportError,
       {Map<String, String>? environmentDefines,
-      super.evaluationMode,
+      required EvaluationMode evaluationMode,
+      bool supportReevaluationForTesting = false})
+      : this._(librarySupport, constantsBackend, component, typeEnvironment,
+            new _ErrorReporter(reportError),
+            environmentDefines: environmentDefines,
+            evaluationMode: evaluationMode,
+            supportReevaluationForTesting: supportReevaluationForTesting);
+
+  TryConstantEvaluator._(
+      DartLibrarySupport librarySupport,
+      ConstantsBackend constantsBackend,
+      Component component,
+      TypeEnvironment typeEnvironment,
+      this.errorReporter,
+      {Map<String, String>? environmentDefines,
+      required super.evaluationMode,
       bool supportReevaluationForTesting = false})
       : _supportReevaluationForTesting = supportReevaluationForTesting,
-        assert((evaluationMode as dynamic) != null),
-        super(
-            librarySupport,
-            constantsBackend,
-            component,
-            environmentDefines ?? const {},
-            typeEnvironment,
-            new _ErrorReporter(reportError),
+        super(librarySupport, constantsBackend, component,
+            environmentDefines ?? const {}, typeEnvironment, errorReporter,
             enableTripleShift: true);
 
-  @override
-  _ErrorReporter get errorReporter => super.errorReporter as _ErrorReporter;
-  // TODO(48820): ^Store another reference to the error reporter with the
-  // refined type and use that.
-
-  // We can't override [ConstantEvaluator.evaluate] and have a nullable
-  // return type.
-  // TODO(48820): Consider using composition. We will need to ensure that
-  // [TryConstantEvaluator] is not referenced via [ConstantEvaluator].
   @override
   Constant evaluate(StaticTypeContext staticTypeContext, Expression node,
       {TreeNode? contextNode}) {