This is an attempt to upstream a set of Proton patches that correct the value of HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\*\~MHz to not be the maximum frequency of the processor, but the calibrated TSC.
Some games like Horizon Zero Dawn and most likely some more obscure benchmark/profiling tools use this as indicated in this forum post: https://community.osr.com/discussion/288014/how-to-find-out-tsc-frequency
The last comment also suggests querying the above registry key for the TSC.
To my understanding the calibration code has been successfully in use for some time now without any known issues.
I tried to be as faithful to the original history as possible with separating out my changes into their own commits.
If everything should be squashed to be prettier, just let me know!
FYI @rbernon
-- v10: wineboot: Compute and write the TSC frequency to registry ~Mhz.