[LoopCacheAnalysis] Enable delinearization of fixed sized arrays

Currently loop cache cost (LCC) cannot analyze fix-sized arrays
since it cannot delinearize them. This patch adds the capability
to delinearize fix-sized arrays to LCC. Most of the code is ported
from DependenceAnalysis.cpp and some refactoring will be done in a
next patch.

Reviewed By: #loopoptwg, Meinersbur

Differential Revision: https://reviews.llvm.org/D122857