Rollup merge of #137619 - Pyr0de:issue_137249, r=fmease

Provide helpful diagnostics for shebang lookalikes

When `[` is not found after a `#!`, a note will be added to the exisiting error

```
error: expected `[`, found `/`
 --> src/main.rs:2:3
  |
2 | #!/usr/bin/env -S cargo +nightly -Zscript
  |   ^ expected `[`
  |
  = note: the token sequence `#!` here looks like the start of a shebang interpreter directive but it is not
  = help: if you meant this to be a shebang interpreter directive, move it to the very start of the file
```

Fixes #137249

r? `@fmease`

0 files changed, 0 insertions, 0 deletions