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
nit: unnecessary change