JIT: Fixed assertion on IsUnusedValue when creating ConditionalSelect nodes around SVE methods (#105730)

* Fixed assertion on IsUnusedValue when creating ConditionalSelect nodes around SVE methods

* Added regression test

* Try/catch

* Make private

* Update Runtime_105484.cs

src/coreclr/jit/lowerarmarch.cpp

@@ -1846,6 +1846,7 @@ GenTree* Lowering::LowerHWIntrinsic(GenTreeHWIntrinsic* node)
         }
         else
         {
+            node->ClearUnusedValue();
             condSelNode->SetUnusedValue();
         }
 

src/tests/JIT/Regression/JitBlue/Runtime_105484/Runtime_105484.cs

@@ -0,0 +1,59 @@
+// Generated by Fuzzlyn v2.2 on 2024-07-30 17:57:54
+// Run on Arm64 Windows
+// Seed: 1755918021774833910-vectort,vector64,vector128,armsve
+// Reduced from 111.7 KiB to 1.0 KiB in 00:00:56
+// Hits JIT assert in Release:
+// Assertion failed '!IsUnusedValue()' in 'Program:Main(Fuzzlyn.ExecutionServer.IRuntime)' during 'Lowering nodeinfo' (IL size 108; hash 0xade6b36b; FullOpts)
+//
+//     File: C:\dev\dotnet\runtime\src\coreclr\jit\gentree.cpp Line: 18154
+//
+using System;
+using System.Runtime.CompilerServices;
+using System.Numerics;
+using System.Runtime.Intrinsics;
+using System.Runtime.Intrinsics.Arm;
+using Xunit;
+
+public class Runtime_105484
+{
+    private static byte[] s_1;
+    private static byte[,, ] s_2;
+    private static Vector<uint> s_5;
+
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static void M()
+    {
+        for (int vr7 = 0; vr7 < 1; vr7++)
+        {
+            var vr8 = Vector128.CreateScalar(1U).AsVector();
+            s_5 = Sve.AndAcross(vr8);
+            try
+            {
+                double vr9 = s_1[0];
+            }
+            finally
+            {
+                var vr10 = (byte)1;
+                var vr11 = Vector128.CreateScalar(vr10).AsVector();
+                var vr12 = s_2[0, 0, 0];
+                var vr13 = Vector.Create<byte>(0);
+                var vr14 = Vector.Create<byte>(0);
+                var vr15 = Sve.CreateMaskForFirstActiveElement(vr13, vr14);
+                s_1[0] = Sve.ConditionalExtractLastActiveElement(vr11, vr12, vr15);
+            }
+        }
+    }
+
+    [Fact]
+    public static void TestEntryPoint()
+    {
+        if (Sve.IsSupported)
+        {
+            try
+            {
+                M();
+            }
+            catch {}
+        }
+    }
+}

src/tests/JIT/Regression/JitBlue/Runtime_105484/Runtime_105484.csproj

@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <Optimize>True</Optimize>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildProjectName).cs" />
+  </ItemGroup>
+</Project>