Fix Cpr001 to work when we run with multiple threads

testsuite/tests/ghc-regress/cpranal/should_compile/all.T

@@ -4,6 +4,7 @@ def f( opts ):
 
 setTestOpts(f)
 
-test('Cpr001_imp', no_clean, compile, [''])
-test('Cpr001', normal, compile, [''])
-clean(['Cpr001_imp.hi', 'Cpr001_imp.o', 'Cpr001_imp.comp.stderr'])
+test('Cpr001',
+     extra_clean(['Cpr001_imp.hi', 'Cpr001_imp.o', 'Cpr001_imp.comp.stderr']),
+     multimod_compile,
+     ['Cpr001', '-v0'])