First few files and initial rebuild

paper-server/patches/sources/com/mojang/datafixers/DataFixerBuilder.java.patch

@@ -0,0 +1,21 @@
+--- a/com/mojang/datafixers/DataFixerBuilder.java
++++ b/com/mojang/datafixers/DataFixerBuilder.java
+@@ -29,8 +_,10 @@
+     private final Int2ObjectSortedMap<Schema> schemas = new Int2ObjectAVLTreeMap<>();
+     private final List<DataFix> globalList = new ArrayList<>();
+     private final IntSortedSet fixerVersions = new IntAVLTreeSet();
++    private final int minDataFixPrecacheVersion; // Paper - Perf: Cache DataFixerUpper Rewrite Rules on demand
+ 
+     public DataFixerBuilder(final int dataVersion) {
++        minDataFixPrecacheVersion = Integer.getInteger("Paper.minPrecachedDatafixVersion", dataVersion+1) * 10; // Paper - Perf: default to precache nothing - mojang stores versions * 10 to allow for 'sub versions'
+         this.dataVersion = dataVersion;
+     }
+ 
+@@ -88,6 +_,7 @@
+             final IntIterator iterator = fixerUpper.fixerVersions().iterator();
+             while (iterator.hasNext()) {
+                 final int versionKey = iterator.nextInt();
++                if (versionKey < minDataFixPrecacheVersion) continue; // Paper - Perf: Cache DataFixerUpper Rewrite Rules on demand
+                 final Schema schema = schemas.get(versionKey);
+                 for (final String typeName : schema.types()) {
+                     if (!requiredTypeNames.contains(typeName)) {

paper-server/patches/sources/com/mojang/datafixers/util/Either.java.patch

@@ -0,0 +1,38 @@
+--- a/com/mojang/datafixers/util/Either.java
++++ b/com/mojang/datafixers/util/Either.java
+@@ -22,7 +_,7 @@
+     }
+ 
+     private static final class Left<L, R> extends Either<L, R> {
+-        private final L value;
++        private final L value; private Optional<L> valueOptional; // Paper - Perf: Reduce Either Optional allocation
+ 
+         public Left(final L value) {
+             this.value = value;
+@@ -51,7 +_,7 @@
+ 
+         @Override
+         public Optional<L> left() {
+-            return Optional.of(value);
++            return this.valueOptional == null ? this.valueOptional = Optional.of(this.value) : this.valueOptional; // Paper - Perf: Reduce Either Optional allocation
+         }
+ 
+         @Override
+@@ -83,7 +_,7 @@
+     }
+ 
+     private static final class Right<L, R> extends Either<L, R> {
+-        private final R value;
++        private final R value; private Optional<R> valueOptional; // Paper - Perf: Reduce Either Optional allocation
+ 
+         public Right(final R value) {
+             this.value = value;
+@@ -117,7 +_,7 @@
+ 
+         @Override
+         public Optional<R> right() {
+-            return Optional.of(value);
++            return this.valueOptional == null ? this.valueOptional = Optional.of(this.value) : this.valueOptional; // Paper - Perf: Reduce Either Optional allocation
+         }
+ 
+         @Override