Change ExpressionImpl and SpreadElementImpl to extend CollectionElementImpl

Change-Id: I7bb78456cab22a1f8791400ec05978743e209f2d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/442501
Commit-Queue: Konstantin Shcheglov <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>
Reviewed-by: Konstantin Shcheglov <[email protected]>

Author: fshcheglov

pkg/analyzer/lib/src/dart/ast/ast.dart

@@ -8162,8 +8162,8 @@ final class ExpressionFunctionBodyImpl extends FunctionBodyImpl
   }
 }
 
-sealed class ExpressionImpl extends AstNodeImpl
-    implements CollectionElementImpl, Expression {
+sealed class ExpressionImpl extends CollectionElementImpl
+    implements Expression {
   TypeImpl? _staticType;
 
   @override
@@ -22364,8 +22364,8 @@ abstract final class SpreadElement implements CollectionElement {
     GenerateNodeProperty('expression'),
   ],
 )
-final class SpreadElementImpl extends AstNodeImpl
-    implements CollectionElementImpl, SpreadElement {
+final class SpreadElementImpl extends CollectionElementImpl
+    implements SpreadElement {
   @generated
   @override
   final Token spreadOperator;