Fiber.current and Fiber#transfer are available without require 'fiber'

Author: eregon

CHANGELOG.md

@@ -80,6 +80,7 @@ Compatibility:
 * Implement `UnboundMethod#original_name` (@paracycle, @nirvdrum).
 * Implement `Thread#native_thread_id` method (#2733, @horakivo).
 * Modify `Struct#{inspect,to_s}` to match MRI when the struct is nested inside of an anonymous class or module (@st0012, @nirvdrum).
+* `Fiber.current` and `Fiber#transfer` are available without `require 'fiber'` like in CRuby 3.1 (#2733, @eregon).
 
 Performance:
 

lib/truffle/fiber.rb

@@ -1,15 +1 @@
-# truffleruby_primitives: true
-
-# Copyright (c) 2021, 2023 Oracle and/or its affiliates. All rights reserved. This
-# code is released under a tri EPL/GPL/LGPL license. You can use it,
-# redistribute it and/or modify it under the terms of the:
-#
-# Eclipse Public License version 2.0, or
-# GNU General Public License version 2, or
-# GNU Lesser General Public License version 2.1.
-
-class Fiber
-  def self.current
-    Primitive.fiber_current
-  end
-end
+# Provided by default

src/main/java/org/truffleruby/core/fiber/FiberNodes.java

@@ -16,7 +16,6 @@
 import org.truffleruby.annotations.Primitive;
 import org.truffleruby.builtins.CoreMethodArrayArgumentsNode;
 import org.truffleruby.builtins.PrimitiveArrayArgumentsNode;
-import org.truffleruby.builtins.PrimitiveNode;
 import org.truffleruby.core.array.RubyArray;
 import org.truffleruby.core.cast.SingleValueCastNode;
 import org.truffleruby.core.cast.SingleValueCastNodeGen;
@@ -321,8 +320,8 @@ protected boolean alive(RubyFiber fiber) {
 
     }
 
-    @Primitive(name = "fiber_current")
-    public abstract static class CurrentNode extends PrimitiveNode {
+    @CoreMethod(names = "current", onSingleton = true)
+    public abstract static class CurrentNode extends CoreMethodArrayArgumentsNode {
 
         @Specialization
         protected RubyFiber current() {

src/main/ruby/truffleruby/post-boot/post-boot.rb

@@ -14,6 +14,7 @@
   begin
     require 'enumerator'
     require 'thread'
+    require 'fiber'
     require 'rational'
     require 'complex'
   rescue LoadError => e