Maintain the solution file persisting dependency information on
disk but update the runtime representation to
Gem::Resolver::DependencyRequest instances which are expected
by the sets when locating matches.
Properly abide by prerelease setting in customized sets and
force prerelease matching when in the builtin set. If a request
is matched on a prerelease, and the request itself is not set
to allow prereleases, update it to ensure successful resolution.
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