Test ghci018 for ghci running splices multiple times (trac #1201)

testsuite/tests/ghc-regress/ghci/scripts/all.T

@@ -20,3 +20,5 @@ test('ghci014', reqlib('QuickCheck'), ghci_script, ['ghci014.script'])
 test('ghci015', normal, ghci_script, ['ghci015.script'])
 test('ghci016', expect_broken(552), ghci_script, ['ghci016.script'])
 test('ghci017', extra_run_opts('-hide-package haskell98'), ghci_script, ['ghci017.script'])
+test('ghci018', expect_broken(1201), ghci_script, ['ghci018.script'])
+

testsuite/tests/ghc-regress/ghci/scripts/ghci018.script

+:set -fth
+:m + Language.Haskell.TH
+$( do runIO $ putStrLn "Q"; [| 'x' |] )
+

testsuite/tests/ghc-regress/ghci/scripts/ghci018.stdout

+Q
+'x'