Do not add self to supertypes

Author: theosotr

src/ir/type_utils.py

@@ -1045,7 +1045,7 @@ class B : A<String>()
     if not same_type and t1.name != t2.name and not t2.is_type_var():
         if not t1.supertypes:
             return {}
-        supertype = t1.supertypes[0]
+        supertype = t1.supertypes[-1]
         return unify_types(supertype, t2, factory, same_type=same_type)
 
     is_type_var = isinstance(t1, tp.TypeParameter)
@@ -1196,7 +1196,7 @@ def replace_targ(targ, type_var_map):
                              for targ in sig.type_args]
         return sig
     if cls_decl.supertypes:
-        return find_sam_fun_signature(context, cls_decl.supertypes[0],
+        return find_sam_fun_signature(context, cls_decl.supertypes[-1],
                                       get_function_type)
     return None
 
@@ -1336,7 +1336,7 @@ def _to_type_var_id(type_con, type_var):
     supertypes = _get_supertypes(t1)
     parent = t1
     while supertypes:
-        st = supertypes[0]
+        st = supertypes[-1]
         if st.is_parameterized():
             type_deps.update({
                 st.name: [_to_type_var_id(st, t_param)

src/ir/types.py

@@ -137,7 +137,7 @@ class Builtin(Type):
 
     def __init__(self, name: str):
         super().__init__(name)
-        self.supertypes = [self]
+        self.supertypes = []
 
     def has_type_variables(self):
         return False