Fixes issue micropython#1012.

Signed-off-by: FuNK3Y <[email protected]>

Signed-off-by: Andrew Leech <[email protected]>

So the behavior matches the comment.

Signed-off-by: Hyx <[email protected]>

This tells the caller that no error has occurred. The child classes can
use this state to do double buffering correctly.

If any fundamental error occurs in submit_xfer, the underlying code will
raise an exception.

Signed-off-by: Hyx <[email protected]>

This implements a very basic `inspect.signature()` function.

At the moment it returns only a simple `Signature` instance with a
`parameters` attribute that holds an `OrderedDict` whose length matches the
arity of the input function (the number of arguments it takes).

So, the following code works and is compatible with CPython:

    def f(a, b, *, c):
        pass

    print(len(inspect.signature(f).parameters))

That should print 3.

Signed-off-by: Damien George <[email protected]>

This commit applies the existing `localtz.patch` patch to add support for
naive datetime objects.  That is, objects that don't have any info about
the current timezone.

This allows `datetime.datetime.now()` to work; prior to this patch it would
raise NotImplementedError.

Although we don't really have support for localtime vs gmtime on
bare-metal, ports such as the unix port and webassembly port do have this
distinction, and for them being able to do `datetime.datetime.now()` is
quite important (at least, that's what users expect to be able to do).

The associated unittest test has been updated.

This patch changes the size of datetime.mpy: 8466 -> 8897, so +431 bytes.

Signed-off-by: Damien George <[email protected]>

Optimizations applied here are:
- writing once-used helper functions inline in their place of use
- writing once-used constant tuples inline in their place of use (I would
  have used `from micropython import const` but that renders the code not
  runnable under CPython for testing, and also increases code size itself
  for the import)
- renamed _tmod to _t
- renamed _format to _fmt
- optimised timedelta._tuple() slightly

Reduces datetime.mpy by: 8897 -> 8728, so saves 169 bytes.

Signed-off-by: Damien George <[email protected]>