[PATCH 0/2] MR76: ntdll: Set up 32-bit segments to support Wow64 on macOS 10.15+.

[Brendan Shanks (＠bshanks)]

- signal_alloc_thread() and signal_free_thread() mostly match signal_i386.c, but with the difference that first thread’s FS needs to be allocated in signal_init_process(). signal_alloc_thread() is called too early before the Wow TEB is allocated.

- The LDT code is copied from signal_i386.c. Would it be worthwhile to move that into a common file?