add test for #2452

testsuite/tests/ghc-regress/ghci/scripts/2452.script

+:set -fno-implicit-import-qualified
+:t System.IO.hPutStrLn

testsuite/tests/ghc-regress/ghci/scripts/2452.stderr

+
+<interactive>:1:0: Not in scope: `System.IO.hPutStrLn'

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

@@ -49,6 +49,7 @@ test('ghci030', normal, ghci_script, ['ghci030.script'])
 test('ghci031', expect_broken(2138), ghci_script, ['ghci031.script'])
 test('ghci032', if_compiler_lt('ghc', '6.9', skip), ghci_script, ['ghci032.script'])
 test('ghci033', normal, ghci_script, ['ghci033.script'])
+test('2452', normal, ghci_script, ['2452.script'])
 
 test('1914',
      extra_clean(['T1914A.hs', 'T1914B.hs']),