Add tests for -XRecursiveDo

testsuite/tests/ghc-regress/parser/should_compile/all.T

@@ -64,3 +64,5 @@ test('read054', normal, compile, [''])
 test('read055', normal, compile, [''])
 test('read056', normal, compile, [''])
 test('read057', normal, compile, [''])
+test('read058', normal, compile, [''])
+test('read059', normal, compile, [''])

testsuite/tests/ghc-regress/parser/should_compile/read058.hs

+
+{-# OPTIONS_GHC -XRecursiveDo #-}
+
+module Foo where
+
+import Control.Monad.Fix
+
+z :: Maybe [Int]
+z = mdo x <- return (1:x)
+        return (take 4 x)
+

testsuite/tests/ghc-regress/parser/should_compile/read059.hs

+
+{-# LANGUAGE RecursiveDo #-}
+
+module Foo where
+
+import Control.Monad.Fix
+
+z :: Maybe [Int]
+z = mdo x <- return (1:x)
+        return (take 4 x)
+

testsuite/tests/ghc-regress/parser/should_fail/all.T

@@ -46,3 +46,4 @@ test('read036', normal, compile_fail, [''])
 test('read037', normal, compile_fail, [''])
 test('read038', normal, compile_fail, [''])
 test('read039', normal, compile_fail, [''])
+test('read040', normal, compile_fail, [''])

testsuite/tests/ghc-regress/parser/should_fail/read040.hs

+
+module Foo where
+
+import Control.Monad.Fix
+
+z :: Maybe [Int]
+z = mdo x <- return (1:x)
+        return (take 4 x)
+

testsuite/tests/ghc-regress/parser/should_fail/read040.stderr

+
+read040.hs:7:10: parse error on input `<-'