Add a couple more sync impls to mini_core

Author: bjorn3

example/mini_core.rs

@@ -90,8 +90,9 @@ unsafe impl Sync for i16 {}
 unsafe impl Sync for i32 {}
 unsafe impl Sync for isize {}
 unsafe impl Sync for char {}
+unsafe impl Sync for f32 {}
 unsafe impl<'a, T: ?Sized> Sync for &'a T {}
-unsafe impl Sync for [u8; 16] {}
+unsafe impl<T: Sync, const N: usize> Sync for [T; N] {}
 
 #[lang = "freeze"]
 unsafe auto trait Freeze {}