Remove CClassDefNode nogil handling

Cython/Compiler/Nodes.py

@@ -4737,7 +4737,6 @@ class CClassDefNode(ClassDefNode):
     #  doc                string or None
     #  body               StatNode or None
     #  entry              Symtab.Entry
-    #  nogil              boolean
     #  base_type          PyExtensionType or None
     #  buffer_defaults_node DictNode or None Declares defaults for a buffer
     #  buffer_defaults_pos
@@ -4747,7 +4746,6 @@ class CClassDefNode(ClassDefNode):
     buffer_defaults_pos = None
     typedef_flag = False
     api = False
-    nogil = False
     objstruct_name = None
     typeobj_name = None
     check_size = None
@@ -4788,7 +4786,6 @@ class CClassDefNode(ClassDefNode):
             typedef_flag=self.typedef_flag,
             check_size = self.check_size,
             api=self.api,
-            nogil=self.nogil,
             buffer_defaults=self.buffer_defaults(env),
             shadow=self.shadow)
 
@@ -4838,12 +4835,6 @@ class CClassDefNode(ClassDefNode):
                      base_type.name in ('tuple', 'str', 'bytes'):
                 error(base.pos, "inheritance from PyVarObject types like '%s' is not currently supported"
                       % base_type.name)
-            elif base_type.is_extension_type and (base_type.nogil != self.nogil):
-                error(base.pos, """
-inheritance between PyExtensionType and CythonExtensionType is not currently supported
-(trying to make %s inherit from %s)
-"""
-                      % (self.class_name, base_type.name))
             else:
                 self.base_type = base_type
             if env.directives.get('freelist', 0) > 0 and base_type != PyrexTypes.py_object_type:
@@ -4883,7 +4874,6 @@ inheritance between PyExtensionType and CythonExtensionType is not currently sup
             visibility=self.visibility,
             typedef_flag=self.typedef_flag,
             api=self.api,
-            nogil=self.nogil,
             buffer_defaults=self.buffer_defaults(env),
             shadow=self.shadow)