Remove an assert from impHWIntrinsic (#72084)

src/coreclr/jit/hwintrinsic.cpp

@@ -770,12 +770,11 @@ GenTree* Compiler::impHWIntrinsic(NamedIntrinsic        intrinsic,
 
         if (HWIntrinsicInfo::IsMultiReg(intrinsic))
         {
+            // We don't have generic multireg APIs
             assert(sizeBytes == 0);
         }
         else
         {
-            assert(sizeBytes != 0);
-
             // We want to return early here for cases where retType was TYP_STRUCT as per method signature and
             // rather than deferring the decision after getting the simdBaseJitType of arg.
             if (!isSupportedBaseType(intrinsic, simdBaseJitType))
@@ -783,6 +782,7 @@ GenTree* Compiler::impHWIntrinsic(NamedIntrinsic        intrinsic,
                 return nullptr;
             }
 
+            assert(sizeBytes != 0);
             retType = getSIMDTypeForSize(sizeBytes);
         }
     }

src/mono/mono/mini/simd-intrinsics.c

@@ -1129,6 +1129,8 @@ emit_sri_vector (MonoCompile *cfg, MonoMethod *cmethod, MonoMethodSignature *fsi
 	}
 	case SN_Create: {
 		MonoType *etype = get_vector_t_elem_type (fsig->ret);
+		if (!MONO_TYPE_IS_VECTOR_PRIMITIVE (etype))
+			return NULL;
 		if (fsig->param_count == 1 && mono_metadata_type_equal (fsig->params [0], etype))
 			return emit_simd_ins (cfg, klass, type_to_expand_op (etype), args [0]->dreg, -1);
 		else if (is_create_from_half_vectors_overload (fsig))

src/tests/JIT/Regression/JitBlue/Runtime_72081/Runtime_72081.cs

+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System;
+using System.Runtime.CompilerServices;
+using System.Runtime.Intrinsics;
+
+public class Runtime_72081
+{
+    public static int Main()
+    {
+        try
+        {
+            Vector128<UInt128> d1 = default;
+            Vector128<UInt128> d2 = Vector128.Create<UInt128>(111);
+            Vector128<UInt128> x = d1 + d2 * d1;
+            return d1.GetHashCode() + x.GetHashCode();
+        }
+        catch (NotSupportedException)
+        {
+            return 100;
+        }
+    }
+}

src/tests/JIT/Regression/JitBlue/Runtime_72081/Runtime_72081.csproj

+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <Optimize>True</Optimize>
+  </PropertyGroup>
+  <ItemGroup>
+    <Compile Include="$(MSBuildProjectName).cs" />
+  </ItemGroup>
+</Project>
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