Auto merge of #87830 - hkmatsumoto:suggest-brackets-for-array-esque-block-expr, r=estebank

Suggest replacing braces for brackets on array-esque invalid block expr

Newcomers may write `{1, 2, 3}` for making arrays, and the current error message is not informative enough to quickly convince them what is needed to fix the error.

This PR implements a diagnostic for this case, and its output looks like this:
```text
error: this code is interpreted as a block expression, not an array
 --> src/lib.rs:1:22
  |
1 |   const FOO: [u8; 3] = {
  |  ______________________^
2 | |     1, 2, 3
3 | | };
  | |_^
  |
  = note: to define an array, one would use square brackets instead of curly braces
help: try using [] instead of {}
  |
1 | const FOO: [u8; 3] = [
2 |     1, 2, 3
3 | ];
  |
```

Fix #87672

0 files changed, 0 insertions, 0 deletions