Remove __match_args__ field during IR preparation

Author: dosisod

mypyc/irbuild/classdef.py

@@ -625,7 +625,7 @@ def find_attr_initializers(
                 and not isinstance(stmt.rvalue, TempNode)
             ):
                 name = stmt.lvalues[0].name
-                if name == "__slots__":
+                if name in ("__slots__", "__match_args__"):
                     continue
 
                 if name == "__deletable__":

mypyc/irbuild/prepare.py

@@ -224,7 +224,7 @@ def prepare_class_def(
 
         if isinstance(node.node, Var):
             assert node.node.type, "Class member %s missing type" % name
-            if not node.node.is_classvar and name not in ("__slots__", "__deletable__"):
+            if not node.node.is_classvar and name not in ("__slots__", "__deletable__", "__match_args__"):
                 ir.attributes[name] = mapper.type_to_rtype(node.node.type)
         elif isinstance(node.node, (FuncDef, Decorator)):
             prepare_method_def(ir, module_name, cdef, mapper, node.node)