Fix DocStyle object creation

Author: soutaro

lib/rbs/ast/ruby/members.rb

@@ -388,7 +388,7 @@ def self.build(leading_block, trailing_block, variables, node)
               end
             end
 
-            unless type_annotations
+            if !type_annotations && (return_annotation || !param_annotations.empty?)
               doc_style, unused_params = DocStyle.build(param_annotations, return_annotation, node)
               type_annotations = doc_style
               unused_annotations.concat(unused_params)

test/rbs/inline_parser_test.rb

@@ -163,7 +163,7 @@ def bar = "" #: void
       decl.members[1].tap do |member|
         assert_instance_of RBS::AST::Ruby::Members::DefMember, member
         assert_instance_of Array, member.annotations
-        assert_equal ["() -> untyped"], member.overloads.map { _1.method_type.to_s }
+        assert_equal ["(?) -> untyped"], member.overloads.map { _1.method_type.to_s }
       end
     end
   end
@@ -187,7 +187,7 @@ def foo #: void[
       decl.members[0].tap do |member|
         assert_instance_of RBS::AST::Ruby::Members::DefMember, member
         assert_instance_of Array, member.annotations
-        assert_equal ["() -> untyped"], member.overloads.map { _1.method_type.to_s }
+        assert_equal ["(?) -> untyped"], member.overloads.map { _1.method_type.to_s }
       end
     end
   end