Add atomically'

Co-authored-by: Jan Beinke <git@janbeinke.com>

stm-ltd/src/Control/Concurrent/STM/Class.hs

@@ -15,6 +15,8 @@ module Control.Concurrent.STM.Class (
   -- ** STM'
   STM',
   runSTM',
+  atomically',
+
   -- *** Capabilities
   RetryMode(..),
   CanRetry,
@@ -132,6 +134,7 @@ import Control.Concurrent.STM (STM)
 import Control.Concurrent.STM qualified as STM
 import Control.Concurrent.STM.Class.TH
 import Control.Monad.Catch
+import Control.Monad.IO.Class
 import Control.Monad.Fix (MonadFix)
 import Control.Monad.Trans.Class (lift)
 import Control.Monad.Trans.RWS (RWST)
@@ -235,6 +238,11 @@ runSTM' :: MonadSTM m => STM' r t a -> m a
 runSTM' (STM' f) = liftSTM f
 {-# INLINABLE runSTM' #-}
 
+atomically' :: MonadIO m => STM' CanRetry CanThrow a -> m a
+atomically' = liftIO . STM.atomically . runSTM'
+{-# INLINABLE atomically' #-}
+
+
 noRetry :: MonadSTM' r t m => STM' NoRetry t a -> m a
 noRetry = unsafeLimitSTM . runSTM'
 {-# INLINABLE noRetry #-}