Hello,

I noticed that emacs-module.c contains duplicate 
module_non_local_exit_check() checks and 
module_assert_thread/module_assert_env asserts, mostly performed at the 
same point in program sequentially.

The module_non_local_exit_check() checks happen in 
MODULE_HANDLE_NONLOCAL_EXIT and MODULE_FUNCTION_BEGIN_NO_CATCH macros. 
The MODULE_HANDLE_NONLOCAL_EXIT is never used by itself, only as part of 
MODULE_FUNCTION_BEGIN which starts with MODULE_FUNCTION_BEGIN_NO_CATCH 
that performs the check.

In addition, there're 6 "Implementation of runtime and environment 
functions" rules outlined where MODULE_HANDLE_NONLOCAL_EXIT should be 
called at step 4 but module_non_local_exit_check() is supposed to have 
already happened at step 3 so documentation does not seem to intend for 
the check to be repeated in MODULE_HANDLE_NONLOCAL_EXIT.

Regarding asserts my observation is that module_non_local_exit_check() 
already contains module_assert_thread and module_assert_env so there's 
no need to do asserts if first thing we do is call 
module_non_local_exit_check.

Regards,
Sergey