tests/uctypes_sizeof_od: Test for using OrderedDict as struct descriptor

Just a copy of uctypes_sizeof.py with minimal changes.

tests/extmod/uctypes_sizeof_od.py

+try:
+    from ucollections import OrderedDict
+    import uctypes
+except ImportError:
+    print("SKIP")
+    raise SystemExit
+
+desc = OrderedDict({
+    # arr is array at offset 0, of UINT8 elements, array size is 2
+    "arr": (uctypes.ARRAY | 0, uctypes.UINT8 | 2),
+    # arr2 is array at offset 0, size 2, of structures defined recursively
+    "arr2": (uctypes.ARRAY | 0, 2, {"b": uctypes.UINT8 | 0}),
+    "arr3": (uctypes.ARRAY | 2, uctypes.UINT16 | 2),
+    "arr4": (uctypes.ARRAY | 0, 2, {"b": uctypes.UINT8 | 0, "w": uctypes.UINT16 | 1}),
+    "sub": (0, {
+        'b1': uctypes.BFUINT8 | 0 | 4 << uctypes.BF_POS | 4 << uctypes.BF_LEN,
+        'b2': uctypes.BFUINT8 | 0 | 0 << uctypes.BF_POS | 4 << uctypes.BF_LEN,
+    }),
+})
+
+data = bytearray(b"01234567")
+
+S = uctypes.struct(uctypes.addressof(data), desc, uctypes.LITTLE_ENDIAN)
+
+print(uctypes.sizeof(S.arr))
+assert uctypes.sizeof(S.arr) == 2
+
+print(uctypes.sizeof(S.arr2))
+assert uctypes.sizeof(S.arr2) == 2
+
+print(uctypes.sizeof(S.arr3))
+
+try:
+    print(uctypes.sizeof(S.arr3[0]))
+except TypeError:
+    print("TypeError")
+
+print(uctypes.sizeof(S.arr4))
+assert uctypes.sizeof(S.arr4) == 6
+
+print(uctypes.sizeof(S.sub))
+assert uctypes.sizeof(S.sub) == 1
+
+# invalid descriptor
+try:
+    print(uctypes.sizeof([]))
+except TypeError:
+    print("TypeError")

tests/extmod/uctypes_sizeof_od.py.exp

+2
+2
+4
+TypeError
+6
+1
+TypeError