Forceload RenderType/RenderStateShard on the main thread during startup

Fixes launch deadlock with Registrate/Quark

Author: embeddedt

forge/src/main/java/org/embeddedt/modernfix/forge/mixin/core/BootstrapClientMixin.java

@@ -0,0 +1,22 @@
+package org.embeddedt.modernfix.forge.mixin.core;
+
+import net.minecraft.client.renderer.RenderType;
+import net.minecraft.server.Bootstrap;
+import org.embeddedt.modernfix.annotation.ClientOnlyMixin;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+
+@Mixin(Bootstrap.class)
+@ClientOnlyMixin
+public class BootstrapClientMixin {
+    /**
+     * Hack to workaround RenderStateShard deadlock (by loading it early on a single thread). We use validate
+     * here to ensure Forge registries are initialized.
+     */
+    @Inject(method = "validate", at = @At("HEAD"))
+    private static void loadClientClasses(CallbackInfo ci) {
+        RenderType.solid();
+    }
+}