add Alignment::new_unchecked::precondition_check to allowlist

Author: RustyYato

tests/codegen-units/item-collection/opaque-return-impls.rs

@@ -47,6 +47,7 @@ pub fn foo2() -> Box<dyn TestTrait2> {
 //~ MONO_ITEM fn std::alloc::Global::alloc_impl
 //~ MONO_ITEM fn std::boxed::Box::<TestStruct2>::new
 //~ MONO_ITEM fn std::alloc::Layout::from_size_align_unchecked::precondition_check
+//~ MONO_ITEM fn std::ptr::Alignment::new_unchecked::precondition_check
 //~ MONO_ITEM fn std::ptr::NonNull::<T>::new_unchecked::precondition_check
 
 struct Counter {