Move const_drop_in_place test from ptr to manually_drop module

Author: clarfonthey

library/coretests/tests/manually_drop.rs

@@ -27,3 +27,41 @@ fn smoke() {
     drop(x);
     drop(y);
 }
+
+#[test]
+fn const_drop_in_place() {
+    const COUNTER: usize = {
+        use core::cell::Cell;
+
+        let counter = Cell::new(0);
+
+        // only exists to make `Drop` indirect impl
+        #[allow(dead_code)]
+        struct Test<'a>(Dropped<'a>);
+
+        struct Dropped<'a>(&'a Cell<usize>);
+        impl const Drop for Dropped<'_> {
+            fn drop(&mut self) {
+                self.0.set(self.0.get() + 1);
+            }
+        }
+
+        let mut one = ManuallyDrop::new(Test(Dropped(&counter)));
+        let mut two = ManuallyDrop::new(Test(Dropped(&counter)));
+        let mut three = ManuallyDrop::new(Test(Dropped(&counter)));
+        assert!(counter.get() == 0);
+        unsafe {
+            ManuallyDrop::drop(&mut one);
+        }
+        assert!(counter.get() == 1);
+        unsafe {
+            ManuallyDrop::drop(&mut two);
+        }
+        assert!(counter.get() == 2);
+        unsafe {
+            ManuallyDrop::drop(&mut three);
+        }
+        counter.get()
+    };
+    assert_eq!(COUNTER, 3);
+}

library/coretests/tests/ptr.rs

@@ -1,6 +1,6 @@
 use core::cell::RefCell;
 use core::marker::Freeze;
-use core::mem::{ManuallyDrop, MaybeUninit};
+use core::mem::MaybeUninit;
 use core::num::NonZero;
 use core::ptr;
 use core::ptr::*;
@@ -1045,41 +1045,3 @@ fn test_ptr_default() {
     let default = PtrMutDefaultTest::default();
     assert!(default.ptr.is_null());
 }
-
-#[test]
-fn test_const_drop_in_place() {
-    const COUNTER: usize = {
-        use core::cell::Cell;
-
-        let counter = Cell::new(0);
-
-        // only exists to make `Drop` indirect impl
-        #[allow(dead_code)]
-        struct Test<'a>(Dropped<'a>);
-
-        struct Dropped<'a>(&'a Cell<usize>);
-        impl const Drop for Dropped<'_> {
-            fn drop(&mut self) {
-                self.0.set(self.0.get() + 1);
-            }
-        }
-
-        let mut one = ManuallyDrop::new(Test(Dropped(&counter)));
-        let mut two = ManuallyDrop::new(Test(Dropped(&counter)));
-        let mut three = ManuallyDrop::new(Test(Dropped(&counter)));
-        assert!(counter.get() == 0);
-        unsafe {
-            ManuallyDrop::drop(&mut one);
-        }
-        assert!(counter.get() == 1);
-        unsafe {
-            ManuallyDrop::drop(&mut two);
-        }
-        assert!(counter.get() == 2);
-        unsafe {
-            ManuallyDrop::drop(&mut three);
-        }
-        counter.get()
-    };
-    assert_eq!(COUNTER, 3);
-}