Make cypclass automatic lock acquisition be flat and never nested

Cython/Compiler/ExprNodes.py

@@ -14181,7 +14181,6 @@ class CoerceToLockedNode(CoercionNode):
         self.rlock_only = rlock_only
         self.type = arg.type
         temp_arg = arg.coerce_to_temp(env)
-        temp_arg.postpone_subexpr_disposal = True
         # Avoid incrementing the reference count when assigning to the temporary
         # but ensure it will be decremented if it was already incremented previously.
         self.needs_decref = not temp_arg.use_managed_ref
@@ -14224,9 +14223,9 @@ class CoerceToLockedNode(CoercionNode):
     def generate_disposal_code(self, code):
         # Close the scope to release the lock.
         code.putln("}")
-        # Dispose of and free subexpressions.
-        self.arg.generate_subexpr_disposal_code(code)
-        self.arg.free_subexpr_temps(code)
+        # The subexpressions of self.arg are disposed-of and freed
+        # as soon as self.arg is evaluated because it is a temporary.
+
         # Decref only if previously incref-ed.
         if self.needs_decref:
             code.put_xdecref_clear(self.result(), self.ctype(), have_gil=not self.in_nogil_context)