prohibit splitting literal patterns

Before PR #32202, check_match tended to report bogus errors or ICE
when encountering a pattern that split a literal, e.g.

```Rust
match foo {
    "bar" => {},
    &_ => {}
}
```

That PR fixed these issues, but trans::_match generates bad code
when it encounters these matches. MIR trans has that fixed, but
it is waiting for 6 weeks in beta. Report an error when encountering
these instead.

Fixes issue #35044.

0 files changed, 0 insertions, 0 deletions