Add test for #23120

testsuite/tests/hiefile/should_run/T23120.hs

+{-# LANGUAGE GHC2021 #-}
+
+module Main where
+
+import TestUtils
+import qualified Data.Map.Strict as Map
+import Data.Either
+import Data.Maybe
+import GHC.Plugins (nameOccName, occNameString)
+
+f :: Int -> Int -> Bool
+f x = (x ==)
+      -- ^ point
+
+point :: (Int,Int)
+point = (12,10)
+
+main = do
+  (df, hf) <- readTestHie "T23120.hie"
+  let ast = fromMaybe (error "nothing") $ selectPoint hf point
+      idents = sourcedNodeIdents $ sourcedNodeInfo ast
+      names = rights $ Map.keys idents
+  mapM_ (print . occNameString . nameOccName) names

testsuite/tests/hiefile/should_run/T23120.stdout

+"=="
+"$dEq"

testsuite/tests/hiefile/should_run/all.T

@@ -6,3 +6,4 @@ test('RecordDotTypes', [extra_run_opts('"' + config.libdir + '"'), extra_files([
 test('SpliceTypes', [req_th, extra_run_opts('"' + config.libdir + '"'), extra_files(['TestUtils.hs'])], compile_and_run, ['-package ghc -fwrite-ide-info'])
 test('HieVdq', [extra_run_opts('"' + config.libdir + '"'), extra_files(['TestUtils.hs'])], compile_and_run, ['-package ghc -fwrite-ide-info'])
 test('T23540', [extra_run_opts('"' + config.libdir + '"'), extra_files(['TestUtils.hs'])], compile_and_run, ['-package ghc -fwrite-ide-info'])
+test('T23120', [extra_run_opts('"' + config.libdir + '"'), extra_files(['TestUtils.hs'])], compile_and_run, ['-package ghc -fwrite-ide-info'])