This formats all copyright comments according to SPDX formatting guidelines.
Additionally, this resolves the remaining GPLv2 only licensed files by relicensing them to GPLv2.0-or-later.
Instead, we can make it part of the type and make named variables for
them, so they only require one definition (and if they ever change for
whatever reason, they only need to be changed in one spot).
Given the VirtualFile instance isn't stored into the class as a data
member, or written to, this can just be turned into a const reference,
as the constructor doesn't need to make a copy of it.