Grammar updates

Typo fix on grammar documentation

I assumer that's why there were already parentheses around the `':' Type`?

Make type in Param optional

closes rust-analyzer/ungrammar#8

10: Allow type aliases in extern blocks r=jonas-schievink a=jonas-schievink

This is for the unstable feature rust-lang#43467, which rustc uses internally

Co-authored-by: Jonas Schievink <jonasschievink@gmail.com>

closes rust-analyzer/ungrammar#9

11: Allow both const & async modifiers
 r=matklad a=matklad

bors r+
🤖

Co-authored-by: Aleksey Kladov <aleksey.kladov@gmail.com>

12: Fix .gitignore
 r=matklad a=matklad

bors r+
🤖

Co-authored-by: Aleksey Kladov <aleksey.kladov@gmail.com>

I don't really look at the results of the benchmarks anyway, so having
them in the repo creates a false sense of benchmarkdness.

If I get to implementing proper benchmarking, I'd probably stay away
from criterion -- we need something much much simpler for this crate.

23: modernize r=matklad a=matklad



Co-authored-by: Aleksey Kladov <aleksey.kladov@gmail.com>

The Travis workflow was deleted in 3d5b7e3476f91280aedda3900c13838b00d64a9d

perf: Only populate public items in dependency symbol index

Book>Contributing>Testing: Fix typos and distracting word choices

…x-with-modifier-block

Fix .const missing block on with modifier block

Fix not parse never type in inherent impl

Add guard support for replace_if_let_with_match

support rename after adding loop label

Add "msg" and "op" to hidden inlay parameter names

…ture

Fix removed feature `doc_auto_cfg` for smol_str lib

minor: Drop unused `ungrammar` import