[AArch64][SVE] Add the SVE dupq_lane intrinsic

Summary:
Implements the @llvm.aarch64.sve.dupq.lane intrinsic.

As specified in the ACLE, the behaviour of:
  svdupq_lane_u64(data, index)

...is identical to:
  svtbl(data, svadd_x(svptrue_b64(),
                      svand_x(svptrue_b64(), svindex_u64(0, 1), 1),
                      index * 2))

If the index is in the range [0,3], the operation is equivalent
to a single DUP (.q) instruction.

Reviewers: sdesmalen, c-rhodes, cameron.mcinally, efriedma, dancgr, rengolin

Reviewed By: sdesmalen

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

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74734