[Impeller] Adds oval shortcut to DisplayListMatrixClipState::clip{RRect,RSuperellipse} (#164519)

Fixes https://github.com/flutter/flutter/issues/163717

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engine/src/flutter/display_list/utils/dl_matrix_clip_tracker.cc

@@ -89,6 +89,9 @@ void DisplayListMatrixClipState::clipRRect(const DlRoundRect& rrect,
   if (rrect.IsRect()) {
     return clipRect(bounds, op, is_aa);
   }
+  if (rrect.IsOval()) {
+    return clipOval(bounds, op, is_aa);
+  }
   switch (op) {
     case DlClipOp::kIntersect:
       adjustCullRect(bounds, op, is_aa);
@@ -114,6 +117,9 @@ void DisplayListMatrixClipState::clipRSuperellipse(
   if (rse.IsRect()) {
     return clipRect(bounds, op, is_aa);
   }
+  if (rse.IsOval()) {
+    return clipOval(bounds, op, is_aa);
+  }
   switch (op) {
     case DlClipOp::kIntersect:
       adjustCullRect(bounds, op, is_aa);