Rollup merge of #110203 - compiler-errors:rtn-dots, r=eholk

Remove `..` from return type notation

`@nikomatsakis` and I decided that using `..` in the return-type notation syntax is probably overkill.

r? `@eholk` since you reviewed the last one

Since this is piggybacking now totally off of a pre-existing syntax (parenthesized generics), let me know if you need any explanation of the logic here, since it's a bit more complicated now.

compiler/rustc_ast/src/ast.rs

@@ -167,9 +167,6 @@ pub enum GenericArgs {
     AngleBracketed(AngleBracketedArgs),
     /// The `(A, B)` and `C` in `Foo(A, B) -> C`.
     Parenthesized(ParenthesizedArgs),
-    /// Associated return type bounds, like `T: Trait<method(..): Send>`
-    /// which applies the `Send` bound to the return-type of `method`.
-    ReturnTypeNotation(Span),
 }
 
 impl GenericArgs {
@@ -181,7 +178,6 @@ impl GenericArgs {
         match self {
             AngleBracketed(data) => data.span,
             Parenthesized(data) => data.span,
-            ReturnTypeNotation(span) => *span,
         }
     }
 }

compiler/rustc_ast/src/mut_visit.rs

@@ -561,7 +561,6 @@ pub fn noop_visit_generic_args<T: MutVisitor>(generic_args: &mut GenericArgs, vi
     match generic_args {
         GenericArgs::AngleBracketed(data) => vis.visit_angle_bracketed_parameter_data(data),
         GenericArgs::Parenthesized(data) => vis.visit_parenthesized_parameter_data(data),
-        GenericArgs::ReturnTypeNotation(_span) => {}
     }
 }
 

compiler/rustc_ast/src/visit.rs

@@ -482,7 +482,6 @@ where
             walk_list!(visitor, visit_ty, &data.inputs);
             walk_fn_ret_ty(visitor, &data.output);
         }
-        GenericArgs::ReturnTypeNotation(_span) => {}
     }
 }