rust-lang/rust#113941

Fixed in nightly-2023-07-23.

This reverts commit 28eb8e7.

Without this, crates.io does not put a Documentation link on the search page.

    warning: field `0` is never read
      --> tests/test_item.rs:64:37
       |
    64 |                 pub struct S<$life>(&$life ());
       |                            -        ^^^^^^^^^
       |                            |
       |                            field in this struct
    ...
    72 |     m!('a);
       |     ------ in this macro invocation
       |
       = note: `#[warn(dead_code)]` on by default
       = note: this warning originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)
    help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
       |
    64 |                 pub struct S<$life>(());
       |                                     ~~

    warning: empty doc comment
       --> tests/test_item.rs:174:17
        |
    174 |                 #[doc = $doc]
        |                 ^^^^^^^^^^^^^
    ...
    180 |     doc_expr!(stringify!());
        |     ----------------------- in this macro invocation
        |
        = help: consider removing or filling it
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#empty_docs
        = note: `-W clippy::empty-docs` implied by `-W clippy::all`
        = help: to override `-W clippy::all` add `#[allow(clippy::empty_docs)]`
        = note: this warning originates in the macro `doc_expr` (in Nightly builds, run with -Z macro-backtrace for more info)

New in nightly-2024-03-24 from rust-lang/rust#119552.

    warning: field `0` is never read
      --> tests/test_item.rs:64:37
       |
    64 |                 pub struct S<$life>(pub &$life ());
       |                            -        ^^^^^^^^^^^^^
       |                            |
       |                            field in this struct
    ...
    72 |     m!('a);
       |     ------ in this macro invocation
       |
       = note: `#[warn(dead_code)]` on by default
       = note: this warning originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)
    help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
       |
    64 |                 pub struct S<$life>(());
       |                                     ~~

Debugging a recent cargo-outdated bug, it would have been nice not to
wonder whether a rustc version change in GitHub's runner image was a
contributing factor.

    warning: unexpected `cfg` condition name: `no_literal_fromstr`
       --> src/lib.rs:415:15
        |
    415 |     #[cfg(not(no_literal_fromstr))]
        |               ^^^^^^^^^^^^^^^^^^
        |
        = help: expected names are: `clippy`, `debug_assertions`, `doc`, `docsrs`, `doctest`, `feature`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `rustfmt`, `sanitize`, `sanitizer_cfi_generalize_pointers`, `sanitizer_cfi_normalize_integers`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `ub_checks`, `unix`, `windows`
        = help: consider using a Cargo feature instead or adding `println!("cargo::rustc-check-cfg=cfg(no_literal_fromstr)");` to the top of the `build.rs`
        = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
        = note: `#[warn(unexpected_cfgs)]` on by default

    warning: unexpected `cfg` condition value: `protocol_feature_paste`
      --> tests/test_attr.rs:33:26
       |
    33 |                 #[cfg(any(feature = "protocol_feature_" $ret:snake, target_pointer_width = "" $width))]
       |                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the condition
    ...
    42 |     m!(Paste, 64);
       |     ------------- in this macro invocation
       |
       = note: no expected values for `feature`
       = help: consider adding `protocol_feature_paste` as a feature in `Cargo.toml`
       = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
       = note: `#[warn(unexpected_cfgs)]` on by default
       = note: this warning originates in the macro `m` (in Nightly builds, run with -Z macro-backtrace for more info)

Resolve unexpected_cfgs warning