[ScopBuilder] Move buildInvariantEquivalenceClasses function from ScopInfo. NFC.

Refactor Scop and ScopBuilder class. Move
buildInvariantEquivalenceClasses function from Scop class to ScopBuilder
class.

Patch by: Dominik Adamski <adamski.dominik@gmail.com>

Differential Revision: https://reviews.llvm.org/D62351

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@361902 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed