Part of the migration to the new driver. With this commit, the only
failures in the test suite using the new frontend are features we don't
intend to port over. Hooray!
Swift SVN r13198
SILSerializeAll and EmitVerboseSIL are /not/ being moved because they are
options controlling the output, not about SILGen and SIL passes.
No functionality change.
Swift SVN r13197
Plumbing this through to the inliner necessitated the creation of a
SILOptions class (like FrontendOptions and IRGenOptions). I'll move
more things into this soon.
One change: for compatibility with the new driver, the option must be
specified as "-sil-inline-threshold 50" instead of "-sil-inline-threshold=50".
(We're really trying to be consistent about joined-equals vs. separate
in the new frontend.)
Swift SVN r13193
