[AArch64][SVE] Add remaining SVE2 intrinsics for widening DSP operations

Summary:
Implements the following intrinsics:
 - llvm.aarch64.sve.[s|u]mullb_lane
 - llvm.aarch64.sve.[s|u]mullt_lane
 - llvm.aarch64.sve.sqdmullb_lane
 - llvm.aarch64.sve.sqdmullt_lane
 - llvm.aarch64.sve.[s|u]addwb
 - llvm.aarch64.sve.[s|u]addwt
 - llvm.aarch64.sve.[s|u]shllb
 - llvm.aarch64.sve.[s|u]shllt
 - llvm.aarch64.sve.[s|u]subwb
 - llvm.aarch64.sve.[s|u]subwt

Reviewers: sdesmalen, dancgr, efriedma, c-rhodes, rengolin

Reviewed By: sdesmalen

Subscribers: tschuett, kristof.beyls, hiraditya, rkruppe, psnobl, cameron.mcinally, cfe-commits, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73903