Fix locations for intrinsics impls

Author: mbartlett21

library/core/src/intrinsics.rs

@@ -1,7 +1,7 @@
 //! Compiler intrinsics.
 //!
 //! The corresponding definitions are in `compiler/rustc_codegen_llvm/src/intrinsic.rs`.
-//! The corresponding const implementations are in `compiler/rustc_mir/src/interpret/intrinsics.rs`
+//! The corresponding const implementations are in `compiler/rustc_const_eval/src/interpret/intrinsics.rs`
 //!
 //! # Const intrinsics
 //!
@@ -10,7 +10,7 @@
 //!
 //! In order to make an intrinsic usable at compile-time, one needs to copy the implementation
 //! from <https://github.com/rust-lang/miri/blob/master/src/shims/intrinsics.rs> to
-//! `compiler/rustc_mir/src/interpret/intrinsics.rs` and add a
+//! `compiler/rustc_const_eval/src/interpret/intrinsics.rs` and add a
 //! `#[rustc_const_unstable(feature = "foo", issue = "01234")]` to the intrinsic.
 //!
 //! If an intrinsic is supposed to be used from a `const fn` with a `rustc_const_stable` attribute,