clear_def_instance_cache.diff

diff --git a/src/compiler/crystal/codegen/ast.cr b/src/compiler/crystal/codegen/ast.cr
index d42583e..f1453f7 100644
--- a/src/compiler/crystal/codegen/ast.cr
+++ b/src/compiler/crystal/codegen/ast.cr
@@ -69,6 +69,10 @@ module Crystal
           next_def = next_def.next
         end
 
+        if used_by_old_call
+          str << "_" << object_id
+        end
+
         needs_self_type = self_type.try &.passed_as_self?
 
         if args.length > 0 || needs_self_type || uses_block_arg
diff --git a/src/compiler/crystal/semantic/ast.cr b/src/compiler/crystal/semantic/ast.cr
index 3e76394..913c515 100644
--- a/src/compiler/crystal/semantic/ast.cr
+++ b/src/compiler/crystal/semantic/ast.cr
@@ -222,6 +222,9 @@ module Crystal
     property :visibility
     getter :special_vars
 
+    property :used_by_old_call
+    @used_by_old_call = false
+
     def macro_owner=(@macro_owner)
     end
 
diff --git a/src/compiler/crystal/types.cr b/src/compiler/crystal/types.cr
index 345d439..14fb61a 100644
--- a/src/compiler/crystal/types.cr
+++ b/src/compiler/crystal/types.cr
@@ -578,6 +578,7 @@ module Crystal
           if ex_item.is_restriction_of?(item, self)
             list[i] = item
             a_def.previous = ex_item.def
+            clear_def_instance_cache ex_item.def.object_id
             return ex_item.def
           else
             list.insert(i, item)
@@ -589,6 +590,19 @@ module Crystal
       nil
     end
 
+    def clear_def_instance_cache(def_object_id)
+      found_instance = false
+      @def_instances.try &.delete_if do |key, existing_def|
+        match = key.def_object_id == def_object_id
+        if match
+          existing_def.used_by_old_call = true
+          found_instance = true
+        end
+        match
+      end
+      found_instance
+    end
+
     def undef(def_name)
       found_list = @defs.try &.delete def_name
       return false unless found_list