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(0x7fd753b9e438), guarded_by(0x7fd74da5ff08), guarded_by(0x7fd74aa92fd8), guarded_by(0x7fd75311d368)]]
std::unique_ptr<CCoinsViewCache> m_cacheview;