[LVI] Move LVILatticeVal class to separate header file (NFC).

Summary:
This allows sharing the lattice value code between LVI and SCCP (D36656). 

It also adds a `satisfiesPredicate` function, used by D36656.

Reviewers: davide, sanjoy, efriedma

Reviewed By: sanjoy

Subscribers: mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D37591

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314411 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed