Add back-compat indices for 8.3.1
diff --git a/lucene/backward-codecs/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java b/lucene/backward-codecs/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java
index 3502b1d..0e1e5a0 100644
--- a/lucene/backward-codecs/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java
+++ b/lucene/backward-codecs/src/test/org/apache/lucene/index/TestBackwardsCompatibility.java
@@ -322,7 +322,9 @@
     "8.2.0-cfs",
     "8.2.0-nocfs",
     "8.3.0-cfs",
-    "8.3.0-nocfs"
+    "8.3.0-nocfs",
+    "8.3.1-cfs",
+    "8.3.1-nocfs"
   };
 
   public static String[] getOldNames() {
@@ -347,7 +349,8 @@
     "sorted.8.1.0",
     "sorted.8.1.1",
     "sorted.8.2.0",
-    "sorted.8.3.0"
+    "sorted.8.3.0",
+    "sorted.8.3.1"
   };
 
   public static String[] getOldSortedNames() {
diff --git a/lucene/backward-codecs/src/test/org/apache/lucene/index/index.8.3.1-cfs.zip b/lucene/backward-codecs/src/test/org/apache/lucene/index/index.8.3.1-cfs.zip
new file mode 100644
index 0000000..c5e57a2
--- /dev/null
+++ b/lucene/backward-codecs/src/test/org/apache/lucene/index/index.8.3.1-cfs.zip
Binary files differ
diff --git a/lucene/backward-codecs/src/test/org/apache/lucene/index/index.8.3.1-nocfs.zip b/lucene/backward-codecs/src/test/org/apache/lucene/index/index.8.3.1-nocfs.zip
new file mode 100644
index 0000000..c5a174d
--- /dev/null
+++ b/lucene/backward-codecs/src/test/org/apache/lucene/index/index.8.3.1-nocfs.zip
Binary files differ
diff --git a/lucene/backward-codecs/src/test/org/apache/lucene/index/sorted.8.3.1.zip b/lucene/backward-codecs/src/test/org/apache/lucene/index/sorted.8.3.1.zip
new file mode 100644
index 0000000..24e0e4c
--- /dev/null
+++ b/lucene/backward-codecs/src/test/org/apache/lucene/index/sorted.8.3.1.zip
Binary files differ