Implement UnboundMethod#original_name.

Co-authored-by: Ufuk Kayserilioglu <[email protected]>

Author: nirvdrum

CHANGELOG.md

@@ -76,6 +76,7 @@ Compatibility:
 * Fix `Enumerable` methods `each_cons` and `each_slice` to return receiver (#2733, @horakivo)
 * `Module` methods `#private`, `#public`, `#protected`, `#module_function` now returns their arguments like in CRuby 3.1 (#2733, @horakivo)
 * `Kernel#exit!`, killing Fibers and internal errors do not run code in `ensure` clauses anymore, the same as CRuby (@eregon).
+* Implement `UnboundMethod#original_name` (@paracycle, @nirvdrum).
 
 Performance:
 

spec/tags/core/unboundmethod/original_name_tags.txt

@@ -19,6 +19,7 @@
 import org.truffleruby.builtins.PrimitiveArrayArgumentsNode;
 import org.truffleruby.core.Hashing;
 import org.truffleruby.core.array.RubyArray;
+import org.truffleruby.core.cast.ToSymbolNode;
 import org.truffleruby.core.encoding.Encodings;
 import org.truffleruby.core.klass.RubyClass;
 import org.truffleruby.core.module.MethodLookupResult;
@@ -147,6 +148,19 @@ protected RubyModule origin(RubyUnboundMethod unboundMethod) {
 
     }
 
+    @CoreMethod(names = "original_name")
+    public abstract static class OriginalNameNode extends CoreMethodArrayArgumentsNode {
+
+        @Specialization
+        protected RubySymbol originalName(RubyUnboundMethod unboundMethod,
+                @Cached ToSymbolNode toSymbolNode) {
+            String originalName = unboundMethod.method.getSharedMethodInfo().getBacktraceName();
+
+            return toSymbolNode.execute(originalName);
+        }
+
+    }
+
     @CoreMethod(names = "owner")
     public abstract static class OwnerNode extends CoreMethodArrayArgumentsNode {