const-stabilize std::mem::needs_drop

src/libcore/mem.rs

@@ -459,7 +459,6 @@ pub fn align_of_val<T: ?Sized>(val: &T) -> usize {
 /// ```
 #[inline]
 #[stable(feature = "needs_drop", since = "1.21.0")]
-#[rustc_const_unstable(feature = "const_needs_drop")]
 pub const fn needs_drop<T>() -> bool {
     intrinsics::needs_drop::<T>()
 }

src/test/run-pass/const-needs_drop.rs

@@ -1,5 +1,3 @@
-#![feature(const_needs_drop)]
-
 use std::mem;
 
 struct Trivial(u8, f32);