Rollup merge of rust-lang#132341 - compiler-errors:raw-lt-prefix-id, r=chenyukang

Reject raw lifetime followed by `'`, like regular lifetimes do

See comment. We want to reject cases like `'r#long'id`, which currently gets interpreted as a raw lifetime (`'r#long`) followed by a lifetime (`'id`). This could have alternative lexes, such as an overlong char literal (`'r#long'`) followed by an identifier (`id`). To avoid committing to this in any case, let's reject the whole thing.

`@mattheww,` is this what you were looking for in rust-lang/reference#1603 (comment)? I'd say ignore the details about the specific error message (the fact that this gets reinterpreted as a char literal is 🤷), just that because this causes a lexer error we're effectively saving syntactical space like you wanted.

…r=chenyukang

Reject raw lifetime followed by `'`, like regular lifetimes do

See comment. We want to reject cases like `'r#long'id`, which currently gets interpreted as a raw lifetime (`'r#long`) followed by a lifetime (`'id`). This could have alternative lexes, such as an overlong char literal (`'r#long'`) followed by an identifier (`id`). To avoid committing to this in any case, let's reject the whole thing.

`@mattheww,` is this what you were looking for in rust-lang/reference#1603 (comment)? I'd say ignore the details about the specific error message (the fact that this gets reinterpreted as a char literal is 🤷), just that because this causes a lexer error we're effectively saving syntactical space like you wanted.

…ebank

Only error raw lifetime followed by `\'` in edition 2021+

Fixes rust-lang#133479
cc rust-lang#132341

I think this fixes a purely theoretical regression since it only affects edition 2015 (who is using that?) and only in the very rare case of a raw lifetime followed immediately by a lifetime like `'r#a'r`.

…ebank

Only error raw lifetime followed by `\'` in edition 2021+

Fixes rust-lang#133479
cc rust-lang#132341

I think this fixes a purely theoretical regression since it only affects edition 2015 (who is using that?) and only in the very rare case of a raw lifetime followed immediately by a lifetime like `'r#a'r`.

Rollup merge of rust-lang#133482 - compiler-errors:raw-lt-tick, r=estebank

Only error raw lifetime followed by `\'` in edition 2021+

Fixes rust-lang#133479
cc rust-lang#132341

I think this fixes a purely theoretical regression since it only affects edition 2015 (who is using that?) and only in the very rare case of a raw lifetime followed immediately by a lifetime like `'r#a'r`.