Given it's only used in one spot and has a fairly generic name, we can
just specify it directly in the function call. This also the benefit of
automatically moving it.
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.
