Selects a rust-toolchain declared RA based on its date. The earliest (oldest) RA wins and becomes the one that the workspace uses as a whole.

In terms of precedence:

nightly > stable-with-version > stable

With stable-with-version, we invoke the RA with a `--version` arg and attempt to extract a date. Given the same date as a nightly, the nightly RA will win.

fix: Insert a tail `Ok(())` for expr block instead of wrapping with `Ok`

Fixes rust-lang#17728

When type mismatch is `Result<(), E>, ()` or `Option<()>, ()` and target expr is a block expression, it is more reasonable to insert a wrapped unit - `Ok(())` or `Some(())` - as the tail expression of that block than wrapping the entire block with `Ok` or `Some`

feat: Use oldest rustup rust-analyzer when toolchain override is present

Selects a rust-toolchain declared RA based on its date. The earliest (oldest) RA wins and becomes the one that the workspace uses as a whole.

In terms of precedence:

nightly > stable-with-version > stable

With stable-with-version, we invoke the RA with a `--version` arg and attempt to extract a date. Given the same date as a nightly, the nightly RA will win.

Fixes rust-lang#17663

internal: Newtype `ErasedFileAstId`

It wrapping `la_arena::Idx` makes it quite annoying to use

docs: add msvc note to manual

Added note for Windows users to have the latest MSVC to minimize setup issues.

Closes rust-lang#4870

Split out syntax-bridge into a separate crate

This functionality is not really tied to mbe macros, so imo it has no place in that crate.

Subtree update of `rust-analyzer`

r? `@ghost`

CC `@ShoyuVanilla`

…iaskrgr

Rollup of 5 pull requests

Successful merges:

 - rust-lang#128828 (`-Znext-solver` caching)
 - rust-lang#128954 (Explicitly specify type parameter on FromResidual for Option and ControlFlow.)
 - rust-lang#129054 (Subtree update of `rust-analyzer`)
 - rust-lang#129059 (Record the correct target type when coercing fn items/closures to pointers)
 - rust-lang#129071 (Port `run-make/sysroot-crates-are-unstable` to rmake)

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