miri: fix raw pointer dyn receivers

Author: RalfJung

tests/pass/dyn-arbitrary-self.rs

@@ -123,8 +123,35 @@ fn pointers_and_wrappers() {
     assert_eq!(wpw.wrapper_ptr_wrapper(), 7);
 }
 
+fn raw_ptr_receiver() {
+    use std::ptr;
+
+    trait Foo {
+        fn foo(self: *const Self) -> &'static str;
+    }
+
+    impl Foo for i32 {
+        fn foo(self: *const Self) -> &'static str {
+            "I'm an i32!"
+        }
+    }
+
+    impl Foo for u32 {
+        fn foo(self: *const Self) -> &'static str {
+            "I'm a u32!"
+        }
+    }
+
+    let null_i32 = ptr::null::<i32>() as *const dyn Foo;
+    let null_u32 = ptr::null::<u32>() as *const dyn Foo;
+
+    assert_eq!("I'm an i32!", null_i32.foo());
+    assert_eq!("I'm a u32!", null_u32.foo());
+}
+
 fn main() {
     pin_box_dyn();
     stdlib_pointers();
     pointers_and_wrappers();
+    raw_ptr_receiver();
 }