JIT: Properly check spilling around fat pointer calls (#116692)

Author: jakobbotsch

src/coreclr/jit/importercalls.cpp

@@ -1475,8 +1475,7 @@ var_types Compiler::impImportCall(OPCODE                  opcode,
                             varDsc->lvType = call->AsCall()->gtReturnType;
                         }
 
-                        // TODO-Bug: CHECK_SPILL_NONE here looks wrong.
-                        impStoreToTemp(calliSlot, call, CHECK_SPILL_NONE);
+                        impStoreToTemp(calliSlot, call, CHECK_SPILL_ALL);
                         // impStoreToTemp can change src arg list and return type for call that returns struct.
                         var_types type = genActualType(lvaTable[calliSlot].TypeGet());
                         call           = gtNewLclvNode(calliSlot, type);

src/tests/JIT/Regression/JitBlue/Runtime_116689/Runtime_116689.cs

@@ -0,0 +1,28 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Runtime.CompilerServices;
+using Xunit;
+
+public unsafe class Runtime_116689
+{
+    [Fact]
+    public static int TestEntryPoint()
+    {
+        s_value = -1;
+        return Test(&GetVal);
+    }
+
+    private static int s_value;
+    [MethodImpl(MethodImplOptions.NoInlining)]
+    private static unsafe int Test(delegate*<int> foo)
+    {
+        return s_value + foo();
+    }
+
+    private static int GetVal()
+    {
+        s_value = 0;
+        return 101;
+    }
+}

src/tests/JIT/Regression/JitBlue/Runtime_116689/Runtime_116689.csproj

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