(total_cache / 4) + (1 << 23) is at least 8 MiB and nMaxCoinsDBCache is
also 8 MiB, so the minimum between the two will always be
nMaxCoinsDBCache. This is just a simplification and not changing the
result of the calculation.
Co-authored-by: Ryan Ofsky <ryan@ofsky.org>
This is a partial backport of core#31483
https://github.com/bitcoin/bitcoin/pull/31483/commits/8bd5f8a38ce903c05606841ebed1902398cb0b14
Depends on D18578