Adjust span labels for HIDDEN_GLOB_REEXPORTS

[jieyouxu]

Addresses #111378 (comment).

Before This PR

The possibility that the private item comes before the glob re-export was not account for, causing the span label messages to say "but private item here shadows it" before "the name Foo in the type namespace is supposed to be publicly re-exported here".

After This PR

warning: private item shadows public glob re-export
  --> $DIR/hidden_glob_reexports.rs:9:5
   |
LL |     struct Foo;
   |     ^^^^^^^^^^^ the private item here shadows the name `Foo` in the type namespace
...
LL |     pub use self::inner::*;
   |             -------------- but it is supposed to be publicly re-exported here
   |
   = note: `#[warn(hidden_glob_reexports)]` on by default

warning: private item shadows public glob re-export
  --> $DIR/hidden_glob_reexports.rs:27:9
   |
LL |     pub use self::inner::*;
   |             -------------- the name `Foo` in the type namespace is supposed to be publicly re-exported here
LL |
LL |     use self::other::Foo;
   |         ^^^^^^^^^^^^^^^^ but the private item here shadows it

[rustbot]

r? @eholk

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[petrochenkov]

There should be some way to reorder these labels without changing the wording.
ping @rust-lang/wg-diagnostics

[jieyouxu]

There should be some way to reorder these labels without changing the wording.

I could just use span_note, it appears a bit more verbose though

warning: private item shadows public glob re-export
  --> tests/ui/resolve/hidden_glob_reexports.rs:9:5
   |
9  |     struct Foo;
   |     ^^^^^^^^^^^
   |
note: the name `Foo` in the type namespace is supposed to be publicly re-exported here
  --> tests/ui/resolve/hidden_glob_reexports.rs:12:13
   |
12 |     pub use self::inner::*;
   |             ^^^^^^^^^^^^^^
note: but the private item here shadows it
  --> tests/ui/resolve/hidden_glob_reexports.rs:9:5
   |
9  |     struct Foo;
   |     ^^^^^^^^^^^
   = note: `#[warn(hidden_glob_reexports)]` on by default

[petrochenkov]

Let's convert these messages to notes then.
(But diagnostic infra should support doing this for labels too.)
@rustbot author

[petrochenkov]

@bors r+

[bors]

📌 Commit 80176a1 has been approved by petrochenkov

It is now in the queue for this repository.

[estebank]

(But diagnostic infra should support doing this for labels too.)

It's been in our backlog for a while to address this in some mechanized way. For now, we've been manually swapping between span labels and span notes on a case by case basis, like you've done here. Thanks for the ping!