Remove workaround for old Prism

Author: smasato

lib/typeprof/core/ast.rb

@@ -346,8 +346,7 @@ def self.parse_cpath(raw_node, cref)
           break
         when :constant_path_node, :constant_path_target_node
           if raw_node.parent
-            # temporarily support old Prism https://bugs.ruby-lang.org/issues/20467
-            names << (raw_node.respond_to?(:name) ? raw_node.name : raw_node.child.name)
+            names << raw_node.name
             raw_node = raw_node.parent
           else
             return names.reverse

lib/typeprof/core/ast/const.rb

@@ -17,14 +17,8 @@ def initialize(raw_node, lenv)
             @cbase = nil
             @toplevel = true
           end
-          # temporarily support old Prism https://bugs.ruby-lang.org/issues/20467
-          if raw_node.respond_to?(:name)
-            @cname = raw_node.name
-            @cname_code_range = TypeProf::CodeRange.from_node(raw_node.name_loc)
-          else
-            @cname = raw_node.child.name
-            @cname_code_range = TypeProf::CodeRange.from_node(raw_node.child.location)
-          end
+          @cname = raw_node.name
+          @cname_code_range = TypeProf::CodeRange.from_node(raw_node.name_loc)
         else
           raise raw_node.type.to_s
         end