Tie the Verifier class to a Module; NFCI

Tie the Verifier class to a Module; NFCI

Summary:
This commit changes the Verifier class to accept a Module via the
constructor to make it obvious that a specific instance of the class is
only intended to work with a specific module.  The `updateModule` setter
(despite being private) was making this fact less transparent.

There are fields in the `Verifier` class like `DeoptimizeDeclarations`
and `GlobalValueVisited` which are module specific, so a given
Verifier instance will not in fact work across multiple modules today.
This change just makes that more obvious.

The motivation is to make it easy to get to the datalayout of the
module unambiguously.  That is required to verify that `inttoptr` and
`ptrtoint` constant expressions are well typed in the face of
non-integral pointer types.

Reviewers: dexonsmith, bkramer, majnemer, chandlerc

Subscribers: mehdi_amini, mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D23040

llvm-svn: 277409