Split Diagnostics for Uncommon Codepoints: Add List to Display Characters Involved

[HTGAzureX1212]

This Pull Request adds a list of the uncommon codepoints involved in the uncommon_codepoints lint, as outlined as a first step in #120228.

Example rendered diagnostic:

error: identifier contains uncommon Unicode codepoints: 'µ'
  --> $DIR/lint-uncommon-codepoints.rs:3:7
   |
LL | const µ: f64 = 0.000001;
   |       ^
   |
note: the lint level is defined here
  --> $DIR/lint-uncommon-codepoints.rs:1:9
   |
LL | #![deny(uncommon_codepoints)]
   |         ^^^^^^^^^^^^^^^^^^^

[rustbot]

r? @cjgillot

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[rustbot]

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

Some changes might have occurred in exhaustiveness checking

cc @Nadrieril

Some changes occurred to MIR optimizations

cc @rust-lang/wg-mir-opt

Some changes might have occurred in exhaustiveness checking

cc @Nadrieril

rustc_macros::diagnostics was changed

cc @davidtwco, @compiler-errors, @TaKO8Ki

Some changes occurred to the CTFE / Miri engine

cc @rust-lang/miri

[rustbot]

There are merge commits (commits with multiple parents) in your changes. We have a no merge policy so these commits will need to be removed for this pull request to be merged.

You can start a rebase with the following commands:

$ # rebase
$ git rebase -i master
$ # delete any merge commits in the editor that appears
$ git push --force-with-lease

The following commits are merge commits:

• 84e8026

[HTGAzureX1212]

Hold on, let me retry this-

[Manishearth]

looks like you're having trouble making the PR, but your approach in the code is right!!

[HTGAzureX1212]

Please see #120259 for the new PR.