Skip TH_repPrim and TH_repPrimOutput for GHC 6.8

They now use Word literals, which 6.8 doesn't support.

testsuite/tests/ghc-regress/th/all.T

@@ -12,9 +12,9 @@ test('TH_mkName', normal, compile, ['-v0'])
 test('TH_repE1', normal, compile, [''])
 test('TH_repE2', normal, compile_and_run, [''])
 test('TH_repE3', normal, compile, [''])
-test('TH_repPrim', normal, compile, ['-v0'])
+test('TH_repPrim', if_compiler_lt('ghc','6.9', skip), compile, ['-v0'])
 test('TH_spliceGuard', normal, compile, ['-v0'])
-test('TH_repPrimOutput', normal, compile_and_run, [''])
+test('TH_repPrimOutput', if_compiler_lt('ghc','6.9', skip), compile_and_run, [''])
 test('TH_repGuard', normal, compile, ['-v0'])
 test('TH_repGuardOutput', normal, compile_and_run, [''])
 test('TH_repPatSig', normal, compile_fail, [''])