tests: Skip extmod machine tests when target is WiPy.

tests/run-tests

@@ -197,6 +197,8 @@ def run_tests(pyb, tests, args):
             skip_tests.add('extmod/zlibd_decompress.py')    # requires zlib
             skip_tests.add('extmod/ujson_dumps_float.py')   # requires floating point
             skip_tests.add('extmod/ujson_loads_float.py')   # requires floating point
+            skip_tests.add('extmod/machine1.py')            # raw memory access not supported by WiPy
+            skip_tests.add('extmod/machine_mem.py')         # raw memory access not supported by WiPy
             skip_tests.add('basics/exception_chain.py')     # warning is not printed
 
     # Some tests are known to fail on 64-bit machines