tests: Fix uctypes tests to run on 64bit arch; enable more native tests.

tests/basics/bytes.py

@@ -33,11 +33,6 @@ print(bytes(3))
 print(bytes([3, 2, 1]))
 print(bytes(range(5)))
 
-def gen():
-    for i in range(4):
-        yield i
-print(bytes(gen()))
-
 # Make sure bytes are not mistreated as unicode
 x = b"\xff\x8e\xfe}\xfd\x7f"
 print(len(x))