Fix test for size_of_val and align_of_val panicking on extern types

Author: bjorn3

example/mini_core_hello_world.rs

@@ -337,17 +337,6 @@ fn main() {
     static REF2: &u8 = REF1;
     assert_eq!(*REF1, *REF2);
 
-    extern "C" {
-        type A;
-    }
-
-    fn main() {
-        let x: &A = unsafe { &*(1usize as *const A) };
-
-        assert_eq!(unsafe { intrinsics::size_of_val(x) }, 0);
-        assert_eq!(unsafe { intrinsics::min_align_of_val(x) }, 1);
-    }
-
     #[repr(simd)]
     struct V([f64; 2]);