Add trait type param bounds to ast token collector

Those tokens were not generated correctly from the AST and thus made
some macros erroneous.

gcc/rust/ChangeLog:

	* ast/rust-ast-collector.cc (TokenCollector::visit): Add colon and
	type param bound tokens when collecting a trait ast node.

Signed-off-by: Pierre-Emmanuel Patry <[email protected]>

Author: P-E-P

gcc/rust/ast/rust-ast-collector.cc

@@ -2449,7 +2449,11 @@ TokenCollector::visit (Trait &trait)
     push (Rust::Token::make (TRAIT, trait.get_locus ()));
     push (Rust::Token::make_identifier (UNDEF_LOCATION, std::move (id)));
 
-    visit (trait.get_generic_params ());
+    if (trait.has_generics ())
+      visit (trait.get_generic_params ());
+    if (!trait.get_type_param_bounds ().empty ())
+      push (Rust::Token::make ((COLON), trait.get_locus ()));
+    visit_items_joined_by_separator (trait.get_type_param_bounds (), PLUS);
 
     visit_items_as_block (trait.get_trait_items (), {});
   });