This also removes unused support for `[rev]` in debugger commands, and makes
breakpoint detection slightly more sensible.

This reduces the need to juggle raw tuples, and opens up the possibility of
moving more parts of directive parsing into `line_directive`.

…iaskrgr

Rollup of 8 pull requests

Successful merges:

 - rust-lang#125205 (Fixup Windows verbatim paths when used with the `include!` macro)
 - rust-lang#131049 (Validate args are correct for `UnevaluatedConst`, `ExistentialTraitRef`/`ExistentialProjection`)
 - rust-lang#131549 (Add a note for `?` on a `impl Future<Output = Result<..>>` in sync function)
 - rust-lang#131731 (add `TestFloatParse` to `tools.rs` for bootstrap)
 - rust-lang#131732 (Add doc(plugins), doc(passes), etc. to INVALID_DOC_ATTRIBUTES)
 - rust-lang#132006 (don't stage-off to previous compiler when CI rustc is available)
 - rust-lang#132022 (Move `cmp_in_dominator_order` out of graph dominator computation)
 - rust-lang#132033 (compiletest: Make `line_directive` return a `DirectiveLine`)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup merge of rust-lang#132033 - Zalathar:directive-line, r=jieyouxu

compiletest: Make `line_directive` return a `DirectiveLine`

This reduces the need to juggle raw tuples, and opens up the possibility of moving more parts of directive parsing into `line_directive`.

In order to make the main change possible, this PR also (partly) separates the debugger-command parsing from the main directive parser. That cleanup removes support for `[rev]` in debugger commands, which is not used by any tests.