fix: Search raw identifiers without prefix
When we find references/usages of a raw identifier, we should disregard `r#` prefix because there are keywords one can use without the prefix in earlier editions (see #13034; this bug is actually fallout from the PR). `name`, the text we're searching for, has already been stripped of the prefix, but the text of nodes we compare it to hasn't been.
The second commit is strictly refactoring, I can remove it if it's not much of value.
fix: Don't expand macros in the same expansion tree after overflow
This patch fixes 2 bugs:
- In `Expander::enter_expand_id()` (and in code paths it's called), we never check whether we've reached the recursion limit. Although it hasn't been reported as far as I'm aware, this may cause hangs or stack overflows if some malformed attribute macro is used on associated items.
- We keep expansion even when recursion limit is reached. Take the following for example:
```rust
macro_rules! foo { () => {{ foo!(); foo!(); }} }
fn main() { foo!(); }
```
We keep expanding the first `foo!()` in each expansion and would reach the limit at some point, *after which* we would try expanding the second `foo!()` in each expansion until it hits the limit again. This will (by default) lead to ~2^128 expansions.
This is essentially what's happening in #14074. Unlike rustc, we don't just stop expanding macros when we fail as long as it produces some tokens so that we can provide completions and other services in incomplete macro calls.
This patch provides a method that takes care of recursion depths (`Expander::within_limit()`) and stops macro expansions in the whole macro expansion tree once it detects recursion depth overflow. To be honest, I'm not really satisfied with this fix because it can still be used in unintended ways to bypass overflow checks, and I'm still seeking ways such that misuses are caught by the compiler by leveraging types or something.
Fixes#14074
fix: don't include `r#` prefix in filesystem changes
Fixes#14131
In addition to fix for #14131, this PR adds raw ident validity checks in rename functionality that we've been missing.
Support DidChangeWorkspaceFolders notifications
This PR enables the `WorkspaceFoldersServerCapabilities` capability for rust-analyzer and implemented support for the associated [`DidChangeWorkspaceFolders`](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#workspace_didChangeWorkspaceFolders) notification to allow clients to update the list of `workspaceFolders` sent during initialization.
## Motivation
This allows clients which lazily autodiscover their workspace roots (like the [helix editor](https://github.com/helix-editor/helix) once [my PR](https://github.com/helix-editor/helix/pull/5748) lands) avoid spawning multiple instances of RA. Right now such clients are forced to either:
* greedily discover all LSP roots in the workspace (precludes the ability to respond to new workspace roots)
* spawn multiple instance of rust-analyzer (one for each root)
* restart rust-analyzer whenever a new workspace is added
Some example use-cases are shown [here](https://github.com/helix-editor/helix/pull/5748#issuecomment-1421012523).
This PR will also improve support for VSCode (and Atom) multi workspaces.
## Implementation
The implementation was fairly straightforward as `rust-analyzer` already supports dynamically reloading workspaces, for example on configuration changes. Furthermore, rust-analyzer also already supports auto-discovering internal workspace from the `workspaceFolders` key in the initialization request. Therefore, the necessary logic just needed to be moved to a central place and reused.
