Fix hints

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

Index: pkg/analyzer/lib/src/generated/incremental_resolver.dart
diff --git a/pkg/analyzer/lib/src/generated/incremental_resolver.dart b/pkg/analyzer/lib/src/generated/incremental_resolver.dart
index 5832ef8365a03e585f38a8e9443e5d68d8ca46f2..fe0df9254d5d239ee9ef5d4a8dc24ba0bfc87475 100644
--- a/pkg/analyzer/lib/src/generated/incremental_resolver.dart
+++ b/pkg/analyzer/lib/src/generated/incremental_resolver.dart
@@ -637,19 +637,19 @@ class DeclarationMatcher extends RecursiveAstVisitor {
         element is CompilationUnitElement ? element : element.enclosingElement;
     while (parent != null) {
       if (parent is CompilationUnitElement) {
-        _enclosingUnit = parent as CompilationUnitElement;
+        _enclosingUnit = parent;
         _enclosingLibrary = element.library;
       } else if (parent is ClassElement) {
         if (_enclosingClass == null) {
-          _enclosingClass = parent as ClassElement;
+          _enclosingClass = parent;
         }
       } else if (parent is FunctionTypeAliasElement) {
         if (_enclosingAlias == null) {
-          _enclosingAlias = parent as FunctionTypeAliasElement;
+          _enclosingAlias = parent;
         }
       } else if (parent is ParameterElement) {
         if (_enclosingParameter == null) {
-          _enclosingParameter = parent as ParameterElement;
+          _enclosingParameter = parent;
         }
       }
       parent = parent.enclosingElement;