SB16 audio playback freezes emulation in Windows 95 guest

This bug has been copied automatically from: https://bugs.launchpad.net/qemu/+bug/1873769
Reported by 'Marko Štamcar' on 2020-04-20 :

- QEMU 4.2.93 (v5.0.0-rc3) built from latest git master
20038cd7a8412feeb49c01f6ede89e36c8995472 using MSYS2 on Windows 10 and
launched on same Windows 10

- Launched using "qemu-system-i386.exe -drive format=raw,file=hdd-2gb.img
-soundhw pcspk,sb16 -m 16 -cpu pentium -vga std -cdrom Windows_95.iso
-boot c"

- I have attached video screen capture of the issue

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I decided to make my first ever QEMU build after encountering the dsound
issues using the latest 4.2.0 binary from https://qemu.weilnetz.de/w64/.
In my 5.0.0-rc3 build the sound playback is working correctly, however the
whole Windows 95 UI freezes while sound is playing.