Fix some code holding client world references longer than needed (#4881)

src/main/java/net/minecraftforge/client/MinecraftForgeClient.java

@@ -100,7 +100,7 @@ public class MinecraftForgeClient
         .build(new CacheLoader<Pair<World, BlockPos>, ChunkCache>()
         {
             @Override
-            public ChunkCache load(Pair<World, BlockPos> key) throws Exception
+            public ChunkCache load(Pair<World, BlockPos> key)
             {
                 return new ChunkCache(key.getLeft(), key.getRight().add(-1, -1, -1), key.getRight().add(16, 16, 16), 1);
             }
@@ -118,4 +118,10 @@ public class MinecraftForgeClient
         int z = pos.getZ() & ~0xF;
         return regionCache.getUnchecked(Pair.of(world, new BlockPos(x, y, z)));
     }
+
+    public static void clearRenderCache()
+    {
+        regionCache.invalidateAll();
+        regionCache.cleanUp();
+    }
 }

src/main/java/net/minecraftforge/client/model/pipeline/BlockInfo.java

@@ -94,6 +94,16 @@ public class BlockInfo
         shx = shy = shz = 0;
     }
 
+    public void reset()
+    {
+        this.world = null;
+        this.state = null;
+        this.blockPos = null;
+        cachedTint = -1;
+        cachedMultiplier = -1;
+        shx = shy = shz = 0;
+    }
+
     private float combine(int c, int s1, int s2, int s3, boolean t0, boolean t1, boolean t2, boolean t3)
     {
         if (c  == 0 && !t0) c  = Math.max(0, Math.max(s1, s2) - 1);

src/main/java/net/minecraftforge/client/model/pipeline/ForgeBlockModelRenderer.java

@@ -122,6 +122,7 @@ public class ForgeBlockModelRenderer extends BlockModelRenderer
                 }
             }
         }
+        lighter.resetBlockInfo();
         return !empty;
     }
 }

src/main/java/net/minecraftforge/client/model/pipeline/VertexLighterFlat.java

@@ -302,6 +302,11 @@ public class VertexLighterFlat extends QuadGatheringTransformer
         blockInfo.setBlockPos(blockPos);
     }
 
+    public void resetBlockInfo()
+    {
+        blockInfo.reset();
+    }
+
     public void updateBlockInfo()
     {
         blockInfo.updateShift();