py/objtype: Support passing in an OrderedDict to type() as the locals.

An OrderedDict can now be used for the locals when creating a type
explicitly via type(name, bases, locals).

Signed-off-by: Damien George <damien@micropython.org>

tests/basics/class_ordereddict.py

@@ -0,0 +1,18 @@
+# test using an OrderedDict as the locals to construct a class
+
+try:
+    from ucollections import OrderedDict
+except ImportError:
+    try:
+        from collections import OrderedDict
+    except ImportError:
+        print("SKIP")
+        raise SystemExit
+
+if not hasattr(int, "__dict__"):
+    print("SKIP")
+    raise SystemExit
+
+
+A = type("A", (), OrderedDict(a=1, b=2, c=3, d=4, e=5))
+print([k for k in A.__dict__.keys() if not k.startswith("_")])