accept break017 output (seems to be correct), and enable it in validate

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

@@ -49,11 +49,7 @@ test('break013', normal, ghci_script, ['break013.script'])
 test('break014', normal, ghci_script, ['break014.script'])
 test('break015', expect_broken(1457), ghci_script, ['break015.script'])
 test('break016', normal, ghci_script, ['break016.script'])
-test('break017',
-     [skip_if_fast,
-      normal],
-     ghci_script,
-     ['break017.script'])
+test('break017', normal, ghci_script, ['break017.script'])
 test('break018', normal, ghci_script, ['break018.script'])
 test('break019', normal, ghci_script, ['break019.script'])
 test('break020', normal, ghci_script, ['break020.script'])

testsuite/tests/ghc-regress/ghci.debugger/scripts/break017.stdout

@@ -4,6 +4,6 @@ Logged breakpoint at ../QSort.hs:6:23-37
 _result :: [Char]
 a :: Char
 as :: [Char]
-*** Exception: RTTI error: probably due to :forcing an undefined
-*** Exception: RTTI error: probably due to :forcing an undefined
 as = 'b' : 'c' : (_t1::[Char])
+*** Exception: Prelude.undefined
+as = 'b' : 'c' : (_t2::[Char])