Fix occasional crash due to unsafe concurrency with RenderTypes

src/main/java/org/embeddedt/modernfix/mixin/RenderTypeMixin.java

@@ -0,0 +1,28 @@
+package org.embeddedt.modernfix.mixin;
+
+import com.google.common.base.Preconditions;
+import it.unimi.dsi.fastutil.objects.ObjectOpenCustomHashSet;
+import net.minecraft.client.renderer.RenderType;
+import net.minecraft.client.renderer.vertex.VertexFormat;
+import org.spongepowered.asm.mixin.Final;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Overwrite;
+import org.spongepowered.asm.mixin.Shadow;
+
+import java.util.Collections;
+
+@Mixin(targets = {"net/minecraft/client/renderer/RenderType$Type"})
+public class RenderTypeMixin {
+    @Shadow @Final private static ObjectOpenCustomHashSet<RenderType.Type> TYPES;
+
+    /**
+     * @author embeddedt
+     * @reason synchronize, can be accessed by multiple mods during modloading
+     */
+    @Overwrite
+    private static RenderType.Type getOrCreate(String name, VertexFormat format, int drawMode, int bufferSize, boolean useDelegate, boolean needsSorting, RenderType.State renderState) {
+        synchronized (TYPES){
+            return TYPES.addOrGet(new RenderType.Type(name, format, drawMode, bufferSize, useDelegate, needsSorting, renderState));
+        }
+    }
+}

src/main/resources/META-INF/accesstransformer.cfg

@@ -1 +1,3 @@
 public net.minecraft.client.Minecraft$WorldSelectionType
+public net.minecraft.client.renderer.RenderType$Type
+public net.minecraft.client.renderer.RenderType$Type <init>(Ljava/lang/String;Lnet/minecraft/client/renderer/vertex/VertexFormat;IIZZLnet/minecraft/client/renderer/RenderType$State;)V

src/main/resources/modernfix.mixins.json

@@ -11,7 +11,8 @@
     "SaveFormatAccessor"
   ],
   "client": [
-    "MinecraftMixin"
+    "MinecraftMixin",
+    "RenderTypeMixin"
   ],
   "injectors": {
     "defaultRequire": 1