This is the top layer of the cache hierarchy - it keeps as many coins in memory as can fit per the dbcache setting.
Declared in <validation.h>
[[guarded_by(0x7fb95f93abf8), guarded_by(0x7fb96ab6af18), guarded_by(0x7fb96d9bdf48), guarded_by(0x7fb9873beae8)]]
std::unique_ptr<CCoinsViewCache> m_cacheview;