fix: allow tuple types in abstract types

Author: amaanq

grammar.js

@@ -867,6 +867,7 @@ module.exports = grammar({
         $.removed_trait_bound,
         $.generic_type,
         $.function_type,
+        $.tuple_type,
       )),
     ),
 

test/corpus/declarations.txt

@@ -1038,6 +1038,7 @@ Type aliases
 
 type Inch = u64;
 type Name<T> = Vec<T>;
+type LazyResolve = impl (FnOnce() -> Capture) + Send + Sync + UnwindSafe;
 
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@@ -1052,7 +1053,21 @@ type Name<T> = Vec<T>;
     (generic_type
       (type_identifier)
       (type_arguments
-        (type_identifier)))))
+        (type_identifier))))
+  (type_item
+    (type_identifier)
+    (bounded_type
+      (bounded_type
+        (bounded_type
+          (abstract_type
+            (tuple_type
+              (function_type
+                (type_identifier)
+                (parameters)
+                (type_identifier))))
+          (type_identifier))
+        (type_identifier))
+      (type_identifier))))
 
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 Empty statements