Use SVE1 variants of AddSaturate and SubtractSaturate instructions

[SwapnilGaikwad]

Fixes: #105799

@a74nh @kunalspathak @dotnet/arm64-contrib @TIHan @amanasifkhalid

[SwapnilGaikwad]

Stress tests are passing now

===================Running default===================
------------------- {} -------------------
Passed test: _Sve_ro::JIT.HardwareIntrinsics.Arm._Sve.Program.Sve_AddSaturate_sbyte() : 31
Passed test: _Sve_ro::JIT.HardwareIntrinsics.Arm._Sve.Program.Sve_AddSaturate_short() : 31
Passed test: _Sve_ro::JIT.HardwareIntrinsics.Arm._Sve.Program.Sve_AddSaturate_int() : 31
Passed test: _Sve_ro::JIT.HardwareIntrinsics.Arm._Sve.Program.Sve_AddSaturate_long() : 31
Passed test: _Sve_ro::JIT.HardwareIntrinsics.Arm._Sve.Program.Sve_AddSaturate_byte() : 31
Passed test: _Sve_ro::JIT.HardwareIntrinsics.Arm._Sve.Program.Sve_AddSaturate_ushort() : 31
Passed test: _Sve_ro::JIT.HardwareIntrinsics.Arm._Sve.Program.Sve_AddSaturate_uint() : 31
Passed test: _Sve_ro::JIT.HardwareIntrinsics.Arm._Sve.Program.Sve_AddSaturate_ulong() : 31
Passed test: _Sve_ro::JIT.HardwareIntrinsics.Arm._Sve.Program.Sve_SubtractSaturate_sbyte() : 31
Passed test: _Sve_ro::JIT.HardwareIntrinsics.Arm._Sve.Program.Sve_SubtractSaturate_short() : 31
Passed test: _Sve_ro::JIT.HardwareIntrinsics.Arm._Sve.Program.Sve_SubtractSaturate_int() : 31
Passed test: _Sve_ro::JIT.HardwareIntrinsics.Arm._Sve.Program.Sve_SubtractSaturate_long() : 31
Passed test: _Sve_ro::JIT.HardwareIntrinsics.Arm._Sve.Program.Sve_SubtractSaturate_byte() : 31
Passed test: _Sve_ro::JIT.HardwareIntrinsics.Arm._Sve.Program.Sve_SubtractSaturate_ushort() : 31
Passed test: _Sve_ro::JIT.HardwareIntrinsics.Arm._Sve.Program.Sve_SubtractSaturate_uint() : 31
Passed test: _Sve_ro::JIT.HardwareIntrinsics.Arm._Sve.Program.Sve_SubtractSaturate_ulong() : 31
===================Running jitstress===================
------------------- {'JitMinOpts': '1'} -------------------
------------------- {'JitStress': '2'} -------------------
------------------- {'JitStress': '1', 'TieredCompilation': '1'} -------------------
------------------- {'JitStress': '2', 'TieredCompilation': '1'} -------------------
------------------- {'TailcallStress': '1'} -------------------
------------------- {'ReadyToRun': '0'} -------------------
===================Running jitstressregs===================
------------------- {'JitStressRegs': '1'} -------------------
------------------- {'JitStressRegs': '2'} -------------------
------------------- {'JitStressRegs': '3'} -------------------
------------------- {'JitStressRegs': '4'} -------------------
------------------- {'JitStressRegs': '8'} -------------------
------------------- {'JitStressRegs': '0x10'} -------------------
------------------- {'JitStressRegs': '0x80'} -------------------
------------------- {'JitStressRegs': '0x1000'} -------------------
------------------- {'JitStressRegs': '0x2000'} -------------------
===================Running jitstress2-jitstressregs===================
------------------- {'JitStress': '2', 'JitStressRegs': '1'} -------------------
------------------- {'JitStress': '2', 'JitStressRegs': '2'} -------------------
------------------- {'JitStress': '2', 'JitStressRegs': '3'} -------------------
------------------- {'JitStress': '2', 'JitStressRegs': '4'} -------------------
------------------- {'JitStress': '2', 'JitStressRegs': '8'} -------------------
------------------- {'JitStress': '2', 'JitStressRegs': '0x10'} -------------------
------------------- {'JitStress': '2', 'JitStressRegs': '0x80'} -------------------
------------------- {'JitStress': '2', 'JitStressRegs': '0x1000'} -------------------
------------------- {'JitStress': '2', 'JitStressRegs': '0x2000'} -------------------

[a74nh]

This LGTM to me.

Slightly different fix than multiply.

For multiply, the predicated version is SVE1, unpredicated is SVE2.

For AddSaturate, the predicated version is SVE2, unpredicated is SVE1.

[amanasifkhalid]

LGTM too, thanks!

I did a quick parse of Sve.cs, and looks like the comments for these intrinsics were already correct, so we don't need to update anything else.