Replace memcmp with IsEqualIID macro that doesn't require a size
parameter and remove the unneeded brackets to give more compact and
more readable code.

Tests with native show that during COM calls posted messages aren't
retrieved other than COM calls so change the PeekMessage parameters in
CoWaitForMultipleHandles to duplicate this.

Try to retrieve messages that are COM calls first in
CoWaitForMultipleHandles before retrieving other types.

Put the PeekMessage call of CoWaitForMultipleHandles into a separate
function so that the order and type of the messages retrieved can be
customised in the future.

should depend on whether the current apartment is a single threaded one.

Pass the no yield flag to PeekMessage since we sleep in
MsgWaitForMultipleObjectsEx and the extra context switch is wasteful.

Fixes another return FALSE without SetLastError.

- Fix incorrect data sizes.
- Fix CDDA addressing.
- Implement XAForm2 mode on Linux.