[mlir] [LLVMIR] add all vector reduction intrinsics to LLVM IR dialect

Summary:
This allows for lowering of VectorOps (and others) into a LLVM IR
that maps directly to efficient implementations on the target machines.

http://llvm.org/docs/LangRef.html#experimental-vector-reduction-intrinsics

Reviewers: ftynse, andydavis1, nicolasvasilache, rriddle

Reviewed By: ftynse, rriddle

Subscribers: jfb, mehdi_amini, rriddle, jpienaar, burmako, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, liufengdb, Joonsoo, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74171