h_malloc_disable_memory_tagging fork potential deadlock

[rdevshp]

If h_malloc_disable_memory_tagging is called in one thread, and another thread forks, it can result in a child process with the init_lock locked forever.

[thestinger]

This is now fixed by 212947c. Initialization must happen prior to fork for correctness which is guaranteed by proper hardened_malloc integration. Without proper hardened_malloc integration, it's guaranteed by not abusing high priority constructors to fork which is incorrect.