Auto merge of #25743 - michaelsproul:match-diagnostics, r=nrc

Part of #24407.

Currently the diagnostics for range patterns are a bit wrong:

```rust
fn main() {
    match 5u32 {
        0 ... 10 => (),
        'a' ... 10 => (),
        10 ... 'z' => (),
        "what" ... 10 => (),
        "what" ... "well" => (),
        10 ... "what" => ()
    }
}
```

```
range.rs:4:9: 4:19 error: mismatched types in range:
 expected integral variable,
    found char [E0211]
range.rs:4         'a' ... 10 => (),
                   ^~~~~~~~~~
range.rs:4:9: 4:16 error: only char and numeric types are allowed in range [E0029]
range.rs:4         'a' ... 10 => (),
                   ^~~~~~~
range.rs:4:9: 4:19 error: mismatched types:
 expected `u32`,
    found `char`
(expected u32,
    found char) [E0308]
range.rs:4         'a' ... 10 => (),
                   ^~~~~~~~~~
range.rs:5:9: 5:19 error: mismatched types in range:
 expected char,
    found integral variable [E0211]
range.rs:5         10 ... 'z' => (),
                   ^~~~~~~~~~
range.rs:5:9: 5:15 error: only char and numeric types are allowed in range [E0029]
range.rs:5         10 ... 'z' => (),
                   ^~~~~~
range.rs:6:9: 6:22 error: mismatched types in range:
 expected integral variable,
    found &-ptr [E0211]
range.rs:6         "what" ... 10 => (),
                   ^~~~~~~~~~~~~
range.rs:6:9: 6:19 error: only char and numeric types are allowed in range [E0029]
range.rs:6         "what" ... 10 => (),
                   ^~~~~~~~~~
range.rs:6:9: 6:22 error: mismatched types:
 expected `u32`,
    found `&'static str`
(expected u32,
    found &-ptr) [E0308]
range.rs:6         "what" ... 10 => (),
                   ^~~~~~~~~~~~~
range.rs:7:9: 7:19 error: only char and numeric types are allowed in range [E0029]
range.rs:7         "what" ... "well" => (),
                   ^~~~~~~~~~
range.rs:7:9: 7:26 error: mismatched types:
 expected `u32`,
    found `&'static str`
(expected u32,
    found &-ptr) [E0308]
range.rs:7         "what" ... "well" => (),
                   ^~~~~~~~~~~~~~~~~
range.rs:8:9: 8:22 error: mismatched types in range:
 expected &-ptr,
    found integral variable [E0211]
range.rs:8         10 ... "what" => ()
                   ^~~~~~~~~~~~~
range.rs:8:9: 8:15 error: only char and numeric types are allowed in range [E0029]
range.rs:8         10 ... "what" => ()
                   ^~~~~~
error: aborting due to 12 previous errors
```

The problems here are:

1. The type of the end of the range is used to predict the type of the start (only mildly counter intuitive).
2. E0029 is erroneously generated for `char ... num` and `num ... char`.
2. `u32` is mentioned.
3. Errors which are essentially the same are reported multiple times.

I've attempted to fix this by checking the requirements in a different order. The output I've achieved for the above example is:

```
/home/michael/Temp/range.rs:4:17: 4:22 error: mismatched types in range:
 expected char,
    found integral variable [E0211]
/home/michael/Temp/range.rs:4         'a' ... 10 => (),
                                              ^~~~~
/home/michael/Temp/range.rs:5:16: 5:22 error: mismatched types in range:
 expected integral variable,
    found char [E0211]
/home/michael/Temp/range.rs:5         10 ... 'z' => (),
                                             ^~~~~~
/home/michael/Temp/range.rs:6:9: 6:19 error: only char and numeric types are allowed in range [E0029]
/home/michael/Temp/range.rs:6         "what" ... 10 => (),
                                      ^~~~~~~~~~
/home/michael/Temp/range.rs:6:9: 6:19 help: run `rustc --explain E0029` to see a detailed explanation
/home/michael/Temp/range.rs:6:9: 6:19 note: Start type: &'static str
End type: _
/home/michael/Temp/range.rs:6         "what" ... 10 => (),
                                      ^~~~~~~~~~
/home/michael/Temp/range.rs:7:9: 7:26 error: only char and numeric types are allowed in range [E0029]
/home/michael/Temp/range.rs:7         "what" ... "well" => (),
                                      ^~~~~~~~~~~~~~~~~
/home/michael/Temp/range.rs:7:9: 7:26 help: run `rustc --explain E0029` to see a detailed explanation
/home/michael/Temp/range.rs:7:9: 7:26 note: Start type: &'static str
End type: &'static str
/home/michael/Temp/range.rs:7         "what" ... "well" => (),
                                      ^~~~~~~~~~~~~~~~~
/home/michael/Temp/range.rs:8:16: 8:25 error: only char and numeric types are allowed in range [E0029]
/home/michael/Temp/range.rs:8         10 ... "what" => ()
                                             ^~~~~~~~~
/home/michael/Temp/range.rs:8:16: 8:25 help: run `rustc --explain E0029` to see a detailed explanation
/home/michael/Temp/range.rs:8:16: 8:25 note: Start type: _
End type: &'static str
/home/michael/Temp/range.rs:8         10 ... "what" => ()
                                             ^~~~~~~~~
error: aborting due to 5 previous errors
```

I think this is already tonnes better, but the `Start type/End type` stuff could be neater. I don't think there's really any need to start a `note:` block but I wanted to get some feedback on this. I'd also appreciate advice on how to print the integer types as something other than `_`.

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