Add regression test for old Word32 arithmetic issue (#497)

testsuite/tests/numeric/should_run/T497.hs

+import Data.Word
+
+-- #497: using -O should not make these == 1
+main = do
+  print $ q * 2 + 1
+  print $ q' * 2 + 1
+
+q :: Word32
+q = 0x7FFFFFFF
+
+q' :: Word64
+q' = 0x7FFFFFFFFFFFFFFF

testsuite/tests/numeric/should_run/T497.stdout

+4294967295
+18446744073709551615

testsuite/tests/numeric/should_run/all.T

@@ -67,3 +67,4 @@ test('T10962', omit_ways(['ghci']), compile_and_run, ['-O2'])
 test('T11702', extra_ways(['optasm']), compile_and_run, [''])
 test('T12136', normal, compile_and_run, [''])
 test('T15301', normal, compile_and_run, ['-O2'])
+test('T497', normal, compile_and_run, ['-O'])