Auto merge of #919 - RalfJung:wide-raw, r=RalfJung

test for invalid wide raw ptr

This is the Miri side of https://github.com/rust-lang/rust/pull/63880.

rust-version

@@ -1 +1 @@
-0444b9f66acb5da23dc816e0d8eb59623ba9ea50
+7445622bcb515c822a2fc6e8c57c90478c1a56bb

tests/compile-fail/validity/invalid_wide_raw.rs

@@ -0,0 +1,8 @@
+fn main() {
+    trait T { }
+    #[derive(Debug)]
+    struct S {
+        x: * mut dyn T
+    }
+    dbg!(S { x: unsafe { std::mem::transmute((0usize, 0usize)) } }); //~ ERROR: encountered dangling or unaligned vtable pointer
+}