enable working tests from bugs.txt

tests/bugs.txt

@@ -2,23 +2,15 @@
 # which will be skipped in the normal testing run.
 
 class_attribute_init_values_T18
-numpy_ValueError_T172
 unsignedbehaviour_T184
 missing_baseclass_in_predecl_T262
 cfunc_call_tuple_args_T408
-compile.cpp_operators
-cpp_templated_ctypedef
 cpp_structs
-function_as_method_T494
 closure_inside_cdef_T554
-pure_mode_cmethod_inheritance_T583
 genexpr_iterable_lookup_T600
 for_from_pyvar_loop_T601
-temp_sideeffects_T654
-class_scope_T671
+temp_sideeffects_T654    # not really a bug, Cython warns about it
 slice2_T636
-builtin_subtype_methods_T653
-builtin_float
 inherited_final_method
 
 # CPython regression tests that don't current work: