Add test for #1892 - :info of a bkpt binding panics

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

@@ -51,6 +51,7 @@ test('break021', normal, ghci_script, ['break021.script'])
 test('break024', normal, ghci_script, ['break024.script'])
 test('break025', normal, ghci_script, ['break025.script'])
 test('break026', normal, ghci_script, ['break026.script'])
+test('break027', normal, ghci_script, ['break027.script'])
 
 test('dynbrk001', normal, ghci_script, ['dynbrk001.script'])
 test('dynbrk002', normal, ghci_script, ['dynbrk002.script'])

testsuite/tests/ghc-regress/ghci.debugger/scripts/break027.script

+:l ../Qsort
+:break qsort
+qsort [3,2,1]
+:step
+:i a

testsuite/tests/ghc-regress/ghci.debugger/scripts/break027.stdout

+Breakpoint 0 activated at ../Qsort.hs:(4,0)-(6,54)
+Stopped at ../Qsort.hs:(4,0)-(6,54)
+_result :: [a] = _
+Stopped at ../Qsort.hs:5:15-50
+_result :: [a] = _
+a :: a = _
+left :: [a] = _
+right :: [a] = _
+a :: a 	-- <no location info>