Auto merge of #58361 - GuillaumeGomez:rollup, r=GuillaumeGomez

Rollup of 16 pull requests

Successful merges:

 - #57259 (Update reference of rlibc crate to compiler-builtins crate)
 - #57740 (Use `to_ne_bytes` for converting IPv4Addr to octets)
 - #57926 (Tiny expansion to docs for `core::convert`.)
 - #58157 (Add Cargo.lock automatically adding message)
 - #58203 (rustdoc: display sugared return types for async functions)
 - #58243 (Add trait alias support in rustdoc)
 - #58262 (Add #[must_use] message to Fn* traits)
 - #58295 (std::sys::unix::stdio: explain why we do into_raw)
 - #58297 (Cleanup JS a bit)
 - #58317 (Some writing improvement, conciseness of intro)
 - #58324 (miri: give non-generic functions a stable address)
 - #58332 (operand-to-place copies should never be overlapping)
 - #58345 (When there are multiple filenames, print what got interpreted as filenames)
 - #58346 (rpath computation: explain why we pop())
 - #58350 (Fix failing tidy (line endings on Windows))
 - #58352 (miri value visitor: use `?` in macro)

Failed merges:

r? @ghost

3 files changed, 8 insertions, 5 deletions

diff --git a/src/libcore/convert.rs b/src/libcore/convert.rs
index 203be541e49..d4a1d15e4e7 100644
--- a/src/libcore/convert.rs
+++ b/src/libcore/convert.rs
@@ -17,7 +17,10 @@
 //! [`TryFrom<T>`][`TryFrom`] rather than [`Into<U>`][`Into`] or [`TryInto<U>`][`TryInto`],
 //! as [`From`] and [`TryFrom`] provide greater flexibility and offer
 //! equivalent [`Into`] or [`TryInto`] implementations for free, thanks to a
-//! blanket implementation in the standard library.
+//! blanket implementation in the standard library.  However, there are some cases
+//! where this is not possible, such as creating conversions into a type defined
+//! outside your library, so implementing [`Into`] instead of [`From`] is
+//! sometimes necessary.
 //!
 //! # Generic Implementations
 //!
diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index 78f1c3c0dff..8b728c9414d 100644
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -24,7 +24,7 @@
 //!   often generated by LLVM. Additionally, this library can make explicit
 //!   calls to these functions. Their signatures are the same as found in C.
 //!   These functions are often provided by the system libc, but can also be
-//!   provided by the [rlibc crate](https://crates.io/crates/rlibc).
+//!   provided by the [compiler-builtins crate](https://crates.io/crates/compiler_builtins).
 //!
 //! * `rust_begin_panic` - This function takes four arguments, a
 //!   `fmt::Arguments`, a `&'static str`, and two `u32`'s. These four arguments
diff --git a/src/libcore/ops/function.rs b/src/libcore/ops/function.rs
index 3a1d765f7b8..c69f5fd9896 100644
--- a/src/libcore/ops/function.rs
+++ b/src/libcore/ops/function.rs
@@ -62,7 +62,7 @@
     label="expected an `Fn<{Args}>` closure, found `{Self}`",
 )]
 #[fundamental] // so that regex can rely that `&str: !FnMut`
-#[must_use]
+#[must_use = "closures are lazy and do nothing unless called"]
 pub trait Fn<Args> : FnMut<Args> {
     /// Performs the call operation.
     #[unstable(feature = "fn_traits", issue = "29625")]
@@ -141,7 +141,7 @@ pub trait Fn<Args> : FnMut<Args> {
     label="expected an `FnMut<{Args}>` closure, found `{Self}`",
 )]
 #[fundamental] // so that regex can rely that `&str: !FnMut`
-#[must_use]
+#[must_use = "closures are lazy and do nothing unless called"]
 pub trait FnMut<Args> : FnOnce<Args> {
     /// Performs the call operation.
     #[unstable(feature = "fn_traits", issue = "29625")]
@@ -220,7 +220,7 @@ pub trait FnMut<Args> : FnOnce<Args> {
     label="expected an `FnOnce<{Args}>` closure, found `{Self}`",
 )]
 #[fundamental] // so that regex can rely that `&str: !FnMut`
-#[must_use]
+#[must_use = "closures are lazy and do nothing unless called"]
 pub trait FnOnce<Args> {
     /// The returned type after the call operator is used.
     #[stable(feature = "fn_once_output", since = "1.12.0")]