The setting bootstrap.mlockall is useful on both POSIX-like systems
(POSIX mlockall) and Windows (Win32 VirtualLock). But mlockall is really
a POSIX only thing so the name should not be tied POSIX. This commit
renames the setting to "bootstrap.memory_lock".
Relates #18669
This commit adds documentation for the bootstrap checks and provides
either links or inline guidance for setting the necessary settings to
pass the bootstrap checks.
Relates #18605
Jason Tedor
Clinton Gormley