Revert "Issue 28580. Relax instantiate to bounds."

pkg/analyzer/lib/src/generated/resolver.dart

Index: pkg/analyzer/lib/src/generated/resolver.dart
diff --git a/pkg/analyzer/lib/src/generated/resolver.dart b/pkg/analyzer/lib/src/generated/resolver.dart
index 63d19d28f279242cdd4e88b45db5ab8f3bf57394..a1979d0bd6e23cc4c9ad322a8f35d55da564924a 100644
--- a/pkg/analyzer/lib/src/generated/resolver.dart
+++ b/pkg/analyzer/lib/src/generated/resolver.dart
@@ -8700,7 +8700,7 @@ class TypeOverrideManager_TypeOverrideScope {
  * type aliases.
  */
 class TypeParameterBoundsResolver {
-  final TypeSystem typeSystem;
+  final TypeProvider typeProvider;
   final LibraryElement library;
   final Source source;
   final AnalysisErrorListener errorListener;
@@ -8709,7 +8709,7 @@ class TypeParameterBoundsResolver {
   TypeNameResolver typeNameResolver = null;
 
   TypeParameterBoundsResolver(
-      this.typeSystem, this.library, this.source, this.errorListener);
+      this.typeProvider, this.library, this.source, this.errorListener);
 
   /**
    * Resolve bounds of type parameters of classes, class and function type
@@ -8762,8 +8762,12 @@ class TypeParameterBoundsResolver {
             } else {
               libraryScope ??= new LibraryScope(library);
               typeParametersScope ??= createTypeParametersScope();
-              typeNameResolver ??= new TypeNameResolver(typeSystem,
-                  typeSystem.typeProvider, library, source, errorListener);
+              typeNameResolver ??= new TypeNameResolver(
+                  new TypeSystemImpl(typeProvider),
+                  typeProvider,
+                  library,
+                  source,
+                  errorListener);
               typeNameResolver.nameScope = typeParametersScope;
               _resolveTypeName(bound);
               typeParameterElement.bound = bound.type;