SVE: Avoid explicit input register copying for Sve2.ConvertToSingleOdd*()

[SwapnilGaikwad]

In src/coreclr/jit/hwintrinsiccodegenarm64.cpp, we need to explicitly copy embMaskOp1Reg to targetReg that may be avoided (discussed here).

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[a74nh]

Specifically these bits:

                            case NI_Sve2_ConvertToSingleOdd:
                            case NI_Sve2_ConvertToSingleOddRoundToOdd:
                                // TODO-SVE: Optimise away the explicit copying of `embMaskOp1Reg` to `targetReg`.
                                // For these intrinsics we cannot use movprfx instruction to populate `targetReg` with
                                // `embMaskOp1Reg`. Thus, we need to perform move before the operation.
                                GetEmitter()->emitIns_Mov(INS_sve_mov, emitSize, targetReg, embMaskOp1Reg,
                                                          /* canSkip */ true, INS_OPTS_SCALABLE_S);
                                emitInsHelper(targetReg, maskReg, embMaskOp2Reg);

                        if ((intrinEmbMask.id == NI_Sve2_ConvertToSingleOdd) ||
                            (intrinEmbMask.id == NI_Sve2_ConvertToSingleOddRoundToOdd))
                        {
                            // TODO-SVE: Optimise away the explicit copying of `embMaskOp1Reg` to `targetReg`.
                            // For these intrinsics we cannot use movprfx instruction to populate `targetReg` with
                            // `embMaskOp1Reg`. Thus, we need to perform move before the operation, and then "sel" to
                            // select the active lanes.
                            assert((targetReg != embMaskOp2Reg) || (embMaskOp1Reg == targetReg));
                            GetEmitter()->emitIns_Mov(INS_sve_mov, emitSize, targetReg, embMaskOp1Reg,
                                                      /* canSkip */ true, INS_OPTS_SCALABLE_S);
                            emitInsHelper(targetReg, maskReg, embMaskOp2Reg);
                            GetEmitter()->emitIns_R_R_R_R(INS_sve_sel, emitSize, targetReg, maskReg, targetReg,
                                                          falseReg, opt);

[a74nh]

We should check after the movprfx refactoring whether this issue still exists