Allow custom SpawnPlacementType registration (#4973)

src/main/java/net/minecraftforge/common/util/EnumHelper.java

@@ -21,20 +21,22 @@ package net.minecraftforge.common.util;
 
 import java.lang.reflect.*;
 import java.util.*;
+import java.util.function.BiPredicate;
 
 import com.google.common.base.Predicate;
 import com.google.common.collect.Lists;
 
-import net.minecraft.entity.passive.IAnimals;
 import net.minecraftforge.fml.common.EnhancedRuntimeException;
 import net.minecraftforge.fml.common.FMLLog;
 import net.minecraft.block.BlockPressurePlate.Sensitivity;
 import net.minecraft.block.material.Material;
 import net.minecraft.enchantment.EnumEnchantmentType;
+import net.minecraft.entity.EntityLiving;
 import net.minecraft.entity.EnumCreatureAttribute;
 import net.minecraft.entity.EnumCreatureType;
 import net.minecraft.entity.item.EntityPainting.EnumArt;
 import net.minecraft.entity.passive.HorseArmorType;
+import net.minecraft.entity.passive.IAnimals;
 import net.minecraft.entity.player.EntityPlayer.SleepResult;
 import net.minecraft.item.EnumAction;
 import net.minecraft.item.EnumRarity;
@@ -42,9 +44,11 @@ import net.minecraft.item.Item;
 import net.minecraft.item.Item.ToolMaterial;
 import net.minecraft.item.ItemArmor.ArmorMaterial;
 import net.minecraft.util.SoundEvent;
+import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.RayTraceResult;
 import net.minecraft.util.text.TextFormatting;
 import net.minecraft.world.EnumSkyBlock;
+import net.minecraft.world.IBlockAccess;
 import net.minecraft.world.gen.structure.StructureStrongholdPieces.Stronghold.Door;
 import net.minecraftforge.classloading.FMLForgePlugin;
 import org.apache.commons.lang3.ArrayUtils;
@@ -76,7 +80,8 @@ public class EnumHelper
         {SleepResult.class},
         {ToolMaterial.class, int.class, int.class, float.class, float.class, int.class},
         {EnumRarity.class, TextFormatting.class, String.class},
-        {HorseArmorType.class, String.class, int.class}
+        {HorseArmorType.class, String.class, int.class},
+        {EntityLiving.SpawnPlacementType.class, BiPredicate.class}
     };
 
     @Nullable
@@ -145,6 +150,12 @@ public class EnumHelper
         return addEnum(EnumRarity.class, name, color, displayName);
     }
 
+    @Nullable
+    public static EntityLiving.SpawnPlacementType addSpawnPlacementType(String name, BiPredicate<IBlockAccess, BlockPos> predicate)
+    {
+        return addEnum(EntityLiving.SpawnPlacementType.class, name, predicate);
+    }
+
     /**
      * 
      * @param name the name of the new {@code HorseArmorType}