global_init: assume the EINTR bit by default

global_init: assume the EINTR bit by default

- Removed from global_init since it isn't thread-safe. The symbol will
  still remain to not break compiles, it just won't have any effect going
  forward.

- make the internals NOT loop on EINTR (the opposite from previously).
  It only risks returning from the select/poll/wait functions early, and that
  should be risk-free.

Closes #4840