Add Refinement#refined_class

CHANGELOG.md

@@ -20,6 +20,7 @@ Compatibility:
 * Add `String#bytesplice` (#3039, @itarato).
 * Add `String#byteindex` and `String#byterindex` (#3039, @itarato).
 * Add implementations of `rb_proc_call_with_block`, `rb_proc_call_kw`, `rb_proc_call_with_block_kw` and `rb_funcall_with_block_kw` (#3068, @andrykonchin).
+* Add `Refinement#refined_class` (#3039, @itarato).
 
 Performance:
 

spec/truffleruby.next-specs

@@ -21,3 +21,5 @@ spec/ruby/core/string/bytesplice_spec.rb
 
 spec/ruby/core/string/byteindex_spec.rb
 spec/ruby/core/string/byterindex_spec.rb
+
+spec/ruby/core/refinement/refined_class_spec.rb

src/main/java/org/truffleruby/core/module/ModuleNodes.java

@@ -2584,4 +2584,13 @@ protected Object doClass(RubyClass rubyClass) {
             return rubyClass.isSingleton;
         }
     }
+
+    @Primitive(name = "refined_class")
+    public abstract static class RefinedClassNode extends PrimitiveArrayArgumentsNode {
+
+        @Specialization
+        protected RubyModule refinedClass(RubyModule refinement) {
+            return refinement.fields.getRefinedModule();
+        }
+    }
 }

src/main/ruby/truffleruby/core/refinement.rb

@@ -25,4 +25,8 @@ def import_methods(*modules)
     end
     self
   end
+
+  def refined_class
+    Primitive.refined_class(self)
+  end
 end

test/mri/tests/ruby/test_refinement.rb

@@ -1835,6 +1835,20 @@ def test_used_modules
     assert_equal [ref::RefB, ref::RefA], ref::Combined::USED_MODS
   end
 
+  def test_refined_class
+    refinements = Module.new {
+      refine Integer do
+        int_refinement = self
+      end
+
+      refine String do
+        str_refinement = self
+      end
+    }.refinements
+    assert_equal(Integer, refinements[0].refined_class)
+    assert_equal(String, refinements[1].refined_class)
+  end
+
   def test_warn_setconst_in_refinmenet
     bug10103 = '[ruby-core:64143] [Bug #10103]'
     warnings = [