PinCoerceUnsized trait into core

library/std/src/lib.rs

@@ -342,6 +342,7 @@
 #![feature(maybe_uninit_write_slice)]
 #![feature(panic_can_unwind)]
 #![feature(panic_internals)]
+#![feature(pin_coerce_unsized_trait)]
 #![feature(pointer_is_aligned_to)]
 #![feature(portable_simd)]
 #![feature(prelude_2024)]