Get rid of MSVC's __int64

Use either int64_t, uint64_t or long long and unsigned long long, defined as per C++11 standard

Minecraft.World/AddIslandLayer.cpp

@@ -2,7 +2,7 @@
 #include "net.minecraft.world.level.newbiome.layer.h"
 #include "net.minecraft.world.level.biome.h"
 
-AddIslandLayer::AddIslandLayer(__int64 seedMixup, shared_ptr<Layer>parent) : Layer(seedMixup)
+AddIslandLayer::AddIslandLayer(int64_t seedMixup, shared_ptr<Layer>parent) : Layer(seedMixup)
 {
 	this->parent = parent;
 }