Remove wall-time / unused skip tick protection (#11412)

Spigot still maintains some partial implementation of "tick skipping", a
practice in which the MinecraftServer.currentTick field is updated not
by an increment of one per actual tick, but instead set to
System.currentTimeMillis() / 50. This behaviour means that the tracked
tick may "skip" a tick value in case a previous tick took more than the
expected 50ms.

To compensate for this in important paths, spigot/craftbukkit
implements "wall-time". Instead of incrementing/decrementing ticks on
block entities/entities by one for each call to their tick() method,
they instead increment/decrement important values, like
an ItemEntity's age or pickupDelay, by the difference of
`currentTick - lastTick`, where `lastTick` is the value of
`currentTick` during the last tick() call.

These "fixes" however do not play nicely with minecraft's simulation
distance as entities/block entities implementing the above behaviour
would "catch up" their values when moving from a non-ticking chunk to a
ticking one as their `lastTick` value remains stuck on the last tick in
a ticking chunk and hence lead to a large "catch up" once ticked again.

Paper completely removes the "tick skipping" behaviour (See patch
"Further-improve-server-tick-loop"), making the above precautions
completely unnecessary, which also rids paper of the previous described
incompatibility with non-ticking chunks.

patches/server/0566-Stinger-API.patch

@@ -0,0 +1,57 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Owen1212055 <23108066+Owen1212055@users.noreply.github.com>
+Date: Tue, 22 Jun 2021 23:15:44 -0400
+Subject: [PATCH] Stinger API
+
+
+diff --git a/src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java b/src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java
+index 73719d488d165ec66a0a1f0301a1bd1ba435259a..1f704ba3b67838718913f892d810364ae6a71d54 100644
+--- a/src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java
++++ b/src/main/java/org/bukkit/craftbukkit/entity/CraftLivingEntity.java
+@@ -361,6 +361,11 @@ public class CraftLivingEntity extends CraftEntity implements LivingEntity {
+         }
+         // Paper end
+     }
++    // Paper start - Bee Stinger API
++    @Override
++    public int getBeeStingerCooldown() {
++        return getHandle().removeStingerTime;
++    }
+ 
+     // Paper start - Add methods for working with arrows stuck in living entities
+     @Override
+@@ -375,6 +380,34 @@ public class CraftLivingEntity extends CraftEntity implements LivingEntity {
+     }
+     // Paper end - Add methods for working with arrows stuck in living entities
+ 
++    @Override
++    public void setBeeStingerCooldown(int ticks) {
++        getHandle().removeStingerTime = ticks;
++    }
++
++    @Override
++    public int getBeeStingersInBody() {
++        return getHandle().getStingerCount();
++    }
++
++    @Override
++    public void setBeeStingersInBody(int count) {
++        Preconditions.checkArgument(count >= 0, "New bee stinger amount must be >= 0");
++        getHandle().setStingerCount(count);
++    }
++
++    @Override
++    public void setNextBeeStingerRemoval(final int ticks) {
++        Preconditions.checkArgument(ticks >= 0, "New amount of ticks before next bee stinger removal must be >= 0");
++        this.getHandle().removeStingerTime = ticks;
++    }
++
++    @Override
++    public int getNextBeeStingerRemoval() {
++        return this.getHandle().removeStingerTime;
++    }
++    // Paper end - Bee Stinger API
++
+     @Override
+     public void damage(double amount) {
+         this.damage(amount, this.getHandle().damageSources().generic());