Allow CORINFO_BOX_THIS for primitives and enums (#24644)

We abort R2R compiling methods with `thisTransform == CORINFO_BOX_THIS`. This means we don't R2R compile some methods that do virtual calls on valuetypes (e.g. calling `ToString` on a struct that doesn't itself provide a `ToString` method).

We can't allow this in general, but enums and primitives should be fine.

2 files changed, 22 insertions, 0 deletions

diff --git a/tests/src/readytorun/tests/main.cs b/tests/src/readytorun/tests/main.cs
index 0223a008a6..bcadc37a3b 100644
--- a/tests/src/readytorun/tests/main.cs
+++ b/tests/src/readytorun/tests/main.cs
@@ -59,6 +59,15 @@ class Program
          var iface = (IMyInterface)o;
          Assert.AreEqual(iface.InterfaceMethod(" "), "Interface result");
          Assert.AreEqual(MyClass.TestInterfaceMethod(iface, "+"), "Interface+result");
+
+        // V2 adds override of ToString
+        if (typeof(MyStructWithVirtuals).GetMethod("ToString").DeclaringType == typeof(MyStructWithVirtuals))
+        {
+            // Make sure the constrained call to ToString doesn't box
+            var mystruct = new MyStructWithVirtuals();
+            mystruct.ToString();
+            Assert.AreEqual(mystruct.X, "Overriden");
+        }
     }
 
     static void TestMovedVirtualMethods()
diff --git a/tests/src/readytorun/tests/test.cs b/tests/src/readytorun/tests/test.cs
index 8a6beaea15..508b369bae 100644
--- a/tests/src/readytorun/tests/test.cs
+++ b/tests/src/readytorun/tests/test.cs
@@ -389,6 +389,19 @@ public struct MyChangingHFAStruct
     }
 }
 
+public struct MyStructWithVirtuals
+{
+    public string X;
+
+#if V2
+    public override string ToString()
+    {
+        X = "Overriden";
+        return base.ToString();
+    }
+#endif
+}
+
 public class ByteBaseClass : List<byte>
 {
     public byte BaseByte;