Use generic NonZero.

src/tools/miri/tests/fail/enum-set-discriminant-niche-variant-wrong.rs

@@ -2,7 +2,7 @@
 #![feature(custom_mir)]
 
 use std::intrinsics::mir::*;
-use std::num::NonZeroI32;
+use std::num::NonZero;
 
 // We define our own option type so that we can control the variant indices.
 #[allow(unused)]
@@ -13,7 +13,7 @@ enum Option<T> {
 use Option::*;
 
 #[custom_mir(dialect = "runtime", phase = "optimized")]
-fn set_discriminant(ptr: &mut Option<NonZeroI32>) {
+fn set_discriminant(ptr: &mut Option<NonZero<i32>>) {
     mir! {
         {
             // We set the discriminant to `Some`, which is a NOP since this is the niched variant.

src/tools/miri/tests/fail/function_pointers/abi_mismatch_repr_C.rs

@@ -1,7 +1,7 @@
-use std::num::*;
+use std::num::NonZero;
 
 #[repr(C)]
-struct S1(NonZeroI32);
+struct S1(NonZero<i32>);
 
 #[repr(C)]
 struct S2(i32);
@@ -11,6 +11,6 @@ fn callee(_s: S2) {}
 fn main() {
     let fnptr: fn(S2) = callee;
     let fnptr: fn(S1) = unsafe { std::mem::transmute(fnptr) };
-    fnptr(S1(NonZeroI32::new(1).unwrap()));
+    fnptr(S1(NonZero::new(1).unwrap()));
     //~^ ERROR: calling a function with argument of type S2 passing data of type S1
 }