[NewPM] Attempt to run opt passes specified via -foo-pass under NPM

Summary:
In order to enable mass testing of opt under NPM, specifically passes
specified via -foo-pass.

This is gated under a new opt flag -enable-new-pm.  Currently
the pass flag parser looks for legacy PM passes with the name "foo" (for
opt arg "-foo") and creates a PassInfo for each one. Here we take the
(legacy PM) pass name and try to match it with one defined in (NPM)
PassRegistry.def.  Ultimately if we want all tests to pass like this,
we'll need to port all passes to NPM and register them in
PassRegistry.def under the same name as they were reigstered in the
legacy PM.

Maybe at some point we'll migrate all -foo to --passes=foo, but that
would be after the NPM switch.

Flipping on the flag causes 2XXX failures under check-llvm. By far most
of them are passes either not ported to NPM or don't have the same name
in PassRegistry.def as their old name.

Reviewers: hans, echristo, asbirlea, leonardchan

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D82320