tests: Fixup tests for 3.x on Rosie

tests/basics/class_reverse_op.py

@@ -1,3 +1,6 @@
+import skip_if
+skip_if.no_reverse_ops()
+
 class A:
 
     def __init__(self, v):

tests/circuitpython/nvm_present.py

@@ -1,4 +1,6 @@
 import skip_if
+# TODO(tannewt): Remove this when we add nvm support to 3.x
+skip_if.always()
 skip_if.board_not_in("metro_m0_express", "feather_m0_express", "circuitplayground_express")
 
 import microcontroller

tests/skip_if.py

@@ -27,6 +27,9 @@ def skip():
     print("SKIP")
     raise SystemExit
 
+def always():
+    skip()
+
 def no_reversed():
     import builtins
     if "reversed" not in dir(builtins):
@@ -89,3 +92,13 @@ def no_slice_assign():
         m2[1:3] = m1[0:2]
     except TypeError:
         skip()
+
+
+def no_reverse_ops():
+    class Foo:
+        def __radd__(self, other):
+            pass
+    try:
+        5 + Foo()
+    except TypeError:
+        skip()