Add failing test for NULL pointer

Author: carbotaniuman

tests/compile-fail/permissive_provenance_null.rs

@@ -0,0 +1,14 @@
+// compile-flags: -Zmiri-permissive-provenance
+#![feature(strict_provenance)]
+
+use std::ptr;
+
+fn main() {
+    let x = 5;
+    let x_ptr = &x as *const i32;
+    let x_usize = x_ptr.expose_addr();
+
+    unsafe {
+        let _a = *ptr::from_exposed_addr::<i32>(0).with_addr(x_usize); //~ ERROR attempting a read access using
+    }
+}