[v3 PATCH] mfplat/tests: Add more comprehensive media source tests.

[Marvin]

Hi,

While running your changed tests, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?

Full results can be found at:
https://testbot.winehq.org/JobDetails.pl?Key=65141

Your paranoid android.


=== debian10 (32 bit WoW report) ===

mfplat:
mfplat.c:3047: Test failed: Unexpected refcount 1.
Unhandled exception: page fault on read access to 0x00000009 in 32-bit code (0x658820b7).

Report validation errors:
mfplat:mfplat crashed (c0000005)