MFC r259042:
Do not force to run atexit handlers, which text comes from a dso owning
the handle passed to __cxa_finalize() but which are registered by other
dso, when the process is inside exit(3).
MFC r259043:
Build an allocator for the aligned memory on top of the rtld-private
malloc.
MFC r259044:
For variant II static TLS, properly align tls segments.

MFC r259072:
Cast Elf_Addr to void * to match the free_aligned() argument type.
MFC r258366:
Add assertions to cover all places in the wiring and unwiring code
where MAP_ENTRY_IN_TRANSITION is set or cleared.