Merge rust-analyzer/ungrammar#11

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

bors r+
🤖

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

Author: bors[bot]

src/tools/rust-analyzer/lib/ungrammar/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "ungrammar"
 description = "A DSL for describing concrete syntax trees"
-version = "1.1.3"
+version = "1.1.4"
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/matklad/ungrammar"
 authors = ["Aleksey Kladov <aleksey.kladov@gmail.com>"]

src/tools/rust-analyzer/lib/ungrammar/rust.ungram

@@ -125,7 +125,7 @@ UseTreeList =
 
 Fn =
  Attr* Visibility?
- 'default'? ('async' | 'const')? 'unsafe'? Abi?
+ 'default'? 'const'? 'async'? 'unsafe'? Abi?
  'fn' Name GenericParamList? ParamList RetType? WhereClause?
  (body:BlockExpr | ';')