tests: Update for _io/_collections module having been renamed.

tests/basics/class_store_class.py

@@ -5,7 +5,7 @@
 try:
     from collections import namedtuple
 except ImportError:
-    from _collections import namedtuple
+    from ucollections import namedtuple
 
 _DefragResultBase = namedtuple('DefragResult', [ 'foo', 'bar' ])
 

tests/basics/namedtuple1.py

 try:
     from collections import namedtuple
 except ImportError:
-    from _collections import namedtuple
+    from ucollections import namedtuple
 
 T = namedtuple("Tup", ["foo", "bar"])
 # CPython prints fully qualified name, what we don't bother to do so far

tests/basics/ordereddict1.py

@@ -2,7 +2,7 @@ try:
     from collections import OrderedDict
 except ImportError:
     try:
-        from _collections import OrderedDict
+        from ucollections import OrderedDict
     except ImportError:
         print("SKIP")
         import sys

tests/bench/var-8-namedtuple-1st.py

 import bench
-from _collections import namedtuple
+from ucollections import namedtuple
 
 T = namedtuple("Tup", ["num", "bar"])
 

tests/bench/var-8.1-namedtuple-5th.py

 import bench
-from _collections import namedtuple
+from ucollections import namedtuple
 
 T = namedtuple("Tup", ["foo1", "foo2", "foo3", "foo4", "num"])
 

tests/io/buffered_writer.py

-import _io as io
+import uio as io
 
 try:
     io.BytesIO

tests/io/stringio1.py

-import _io as io
+import uio as io
 
 a = io.StringIO()
 print('io.StringIO' in repr(a))

tests/io/stringio_with.py

-import _io as io
+import uio as io
 
 # test __enter__/__exit__
 with io.StringIO() as b:

tests/misc/print_exception.py

-import _io as io # uPy does not have io module builtin
+import uio as io # uPy does not have io module builtin
 import sys
 if hasattr(sys, 'print_exception'):
     print_exception = sys.print_exception

tests/misc/recursive_data.py

 # This tests that printing recursive data structure doesn't lead to segfault.
-import _io as io
+import uio as io
 
 l = [1, 2, 3, None]
 l[-1] = l