[LICM & MemorySSA] Make limit flags pass tuning options.

Summary:
Make the flags in LICM + MemorySSA tuning options in the old and new
pass managers.

Subscribers: mehdi_amini, jlebar, Prazek, george.burgess.iv, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D60490

llvm-svn: 358772