Add track_caller to transmute_copy

Author: elichai

Diff for: library/core/src/mem/mod.rs

@@ -1054,6 +1054,7 @@ pub const fn copy<T: Copy>(x: &T) -> T {
 /// ```
 #[inline]
 #[must_use]
+#[track_caller]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_const_stable(feature = "const_transmute_copy", since = "1.74.0")]
 pub const unsafe fn transmute_copy<Src, Dst>(src: &Src) -> Dst {