yonatang solution: a jdk8 friendly, no unsafe code, epsilon-gc friendly solution (#499)

* 1bc challenge, but one that will run using jdk 8 without unsafe and still do reasonably well.

* Better hashtable

* the fastest GC is no GC

* cleanups

* increased hash size

* removed Playground.java

* collision-handling allocation free hashmap

* formatting

calculate_average_yonatang.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+#
+#  Copyright 2023 The original authors
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+
+# GC is overrated
+JAVA_OPTS="-XX:+UnlockExperimentalVMOptions -XX:+UseEpsilonGC -XX:+AlwaysPreTouch -Xms512m -Xmx512m"
+java $JAVA_OPTS --class-path target/average-1.0.0-SNAPSHOT.jar dev.morling.onebrc.CalculateAverage_yonatang