Fix comprehensions comment to inlined by pep 709

Python/codegen.c

@@ -4087,9 +4087,11 @@ codegen_call_helper(compiler *c, location loc,
     return codegen_call_helper_impl(c, loc, n, args, NULL, keywords);
 }
 
-/* List and set comprehensions and generator expressions work by creating a
-  nested function to perform the actual iteration. This means that the
-  iteration variables don't leak into the current scope.
+/* List and set comprehensions work by being inlined at the location where
+  they are defined. The isolation of iteration variables is provided by
+  pushing/popping clashing locals on the stack. Generator expressions work
+  by creating a nested function to perform the actual iteration.
+  This means that the iteration variables don't leak into the current scope.
   The defined function is called immediately following its definition, with the
   result of that call being the result of the expression.
   The LC/SC version returns the populated container, while the GE version is