[PATCH2/2] winmm: PlaySound concurrency cleanup.

[Joerg-Cyril.Hoehle at t-systems.com]

Eric,

>sharing a global variable between threads without proper
>sync protection or atomic operation is the wrong thing to do
Which one?
bPlaySoundStop is set and reset within the scope of WINMM_cs.

Actually, there's one error: I should have put it at the exact
same location of the Re/SetEvent(psStopEvent) it replaces,
not outside the loop.  This became apparent as I rethought of
the scenario where 2 concurrent invocations of PlaySound need
to interrupt an already running third one.

I'll resubmit ASAP.

>moreover you're doing several unrelated changes
>in the same patch, please split up
I initially had that as 4-5 patches, then merged them
for not being of significant value individually.

Regards,
       Jörg Höhle