Fix frontend presubmit check on Windows

Change-Id: Ide265d78942718140d3792064694b1f83a1236a9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/350821
Reviewed-by: Jens Johansen <[email protected]>
Commit-Queue: Johnni Winther <[email protected]>

Author: johnniwinther

pkg/front_end/presubmit_helper.dart

@@ -340,8 +340,15 @@ int? _getPathSegmentIndexIfSubEntry(Uri outer, Uri inner) {
   int end = outerPathSegments.length;
   if (outerPathSegments.last == "") end--;
   for (int i = 0; i < end; i++) {
-    if (outerPathSegments[i] != innerPathSegments[i]) {
-      return null;
+    if (Platform.isWindows) {
+      if (outerPathSegments[i].toLowerCase() !=
+          innerPathSegments[i].toLowerCase()) {
+        return null;
+      }
+    } else {
+      if (outerPathSegments[i] != innerPathSegments[i]) {
+        return null;
+      }
     }
   }
   return end;