fix datapacks not being able to modify nether/end (#7588)

patches/server/0005-MC-Dev-fixes.patch

@@ -182,6 +182,30 @@ index 2a6969baca7c07c52223672de58886dd05c032eb..a620e53021e02da1663b8d8b68d429b2
      @Override
      public void write(FriendlyByteBuf buf) {
          buf.writeInt(this.playerId);
+diff --git a/src/main/java/net/minecraft/resources/RegistryLoader.java b/src/main/java/net/minecraft/resources/RegistryLoader.java
+index 858037070db0b0fed07bf542294b76028f0018f9..75f72b568ee2b27c5042da688b62d4e3c5732e09 100644
+--- a/src/main/java/net/minecraft/resources/RegistryLoader.java
++++ b/src/main/java/net/minecraft/resources/RegistryLoader.java
+@@ -73,7 +73,7 @@ public class RegistryLoader {
+     }
+ 
+     private <E> RegistryLoader.ReadCache<E> readCache(ResourceKey<? extends Registry<E>> registryRef) {
+-        return this.readCache.computeIfAbsent(registryRef, (ref) -> {
++        return (RegistryLoader.ReadCache<E>) this.readCache.computeIfAbsent(registryRef, (ref) -> { // Paper - decompile fix
+             return new RegistryLoader.ReadCache();
+         });
+     }
+@@ -83,10 +83,6 @@ public class RegistryLoader {
+     }
+ 
+     public static record Bound(RegistryAccess.Writable access, RegistryLoader loader) {
+-        public Bound(RegistryAccess.Writable writable, RegistryLoader registryLoader) {
+-            this.access = writable;
+-            this.loader = registryLoader;
+-        }
+ 
+         public <E> DataResult<? extends Registry<E>> overrideRegistryFromResources(ResourceKey<? extends Registry<E>> registryRef, Codec<E> codec, DynamicOps<JsonElement> ops) {
+             WritableRegistry<E> writableRegistry = this.access.ownedWritableRegistryOrThrow(registryRef);
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
 index ef128de5fe17231b39edb12a7014291d03cf79ec..868f6799a0e406401eecf18bc939fbdf88f534a2 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java

patches/server/0754-Use-correct-LevelStem-registry-when-loading-default-.patch

@@ -4,9 +4,27 @@ Date: Sat, 16 Oct 2021 17:38:35 -0700
 Subject: [PATCH] Use correct LevelStem registry when loading default
  end/nether
 
+Co-authored-by: Jake Potrebic <jake.m.potrebic@gmail.com>
 
+diff --git a/src/main/java/net/minecraft/resources/RegistryLoader.java b/src/main/java/net/minecraft/resources/RegistryLoader.java
+index 75f72b568ee2b27c5042da688b62d4e3c5732e09..8c3555842202d67793d818c96feda4daa2f08a0c 100644
+--- a/src/main/java/net/minecraft/resources/RegistryLoader.java
++++ b/src/main/java/net/minecraft/resources/RegistryLoader.java
+@@ -42,6 +42,12 @@ public class RegistryLoader {
+         RegistryLoader.ReadCache<E> readCache = this.readCache(registryRef);
+         DataResult<Holder<E>> dataResult = readCache.values.get(entryKey);
+         if (dataResult != null) {
++            // Paper start - register in registry due to craftbukkit running this 3 times instead of once
++            if (registryRef == (ResourceKey) Registry.LEVEL_STEM_REGISTRY && dataResult.result().isPresent()) {
++                // OptionalInt.empty() because the LevelStem registry is only loaded from the resource manager, not the InMemory resource access
++                registry.registerOrOverride(java.util.OptionalInt.empty(), entryKey, dataResult.result().get().value(), dataResult.lifecycle());
++            }
++            // Paper end
+             return dataResult;
+         } else {
+             Holder<E> holder = registry.getOrCreateHolder(entryKey);
 diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
-index a279368fe144bd41d15e5fe5e565412f8b4ef9f7..f877b956859643b4f3d969992f2e515dc490f90c 100644
+index fddb279d161b30d6944495f0de9f6b7e21761a80..df955666723a8cb1e612311f0b8e77fb577d6be5 100644
 --- a/src/main/java/net/minecraft/server/MinecraftServer.java
 +++ b/src/main/java/net/minecraft/server/MinecraftServer.java
 @@ -563,7 +563,14 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa