* vinoski/stderr-eagain/OTP-12942:
  Handle ERRNO_BLOCK in fd_driver async functions

* lukas/erts/fix_ttsl_binary_leak/OTP-12941:
  erts: Fix binary memory leak in ttsl driver

Several users on erlang-questions have reported problems with recent
releases where output to standard_error causes standard_error_sup to
die from receiving an unexpected eagain error. In the fd_driver,
change the fd_async() function to handle EINTR, and change
fd_ready_async() to handle ERRNO_BLOCK. Add a new test to
standard_error_SUITE to generate output to standard_error and ensure
that standard_error_sup does not die. Thanks to Kota Uenishi for
contributing the test case.

* rickard/end-time-fix/OTP-12896:
  Fix calculation of end time

* rickard/monotonic-clock-source/OTP-12895:
  Prefer monotonic time that stop during suspend