* bjorn/stdlib/rand-export_seed/OTP-13162:
  Correct rand:export_seed/0 when there is no prior seed

According to the documentation, rand:export_seed/0 should return
'undefined' if the seed has not been intialized. However, it will
create and return a seed. That means that the following code
will not work as expected:

  case rand:export_seed() of
     undefined -> rand:seen({1,2,3});
     _ -> ok
  end,
  rand:uniform(Range)

Add parentheses around annotated type union elements in map pair
types. The bug was introduced in Erlang/OTP 18.0.

erl_lint:format_error/1 would crash with a function error if
conflicting types were given. That was most easily noticed in the
shell:

  Eshell V7.0.3  (abort with ^G)
  1> <<0/integer-binary>>.
  *** ERROR: Shell process terminated! ***

Noticed-by: Aleksei Magusev

The test suite depended on the compiler to call
erl_lint:format_error/1 to ensure that format_error/1 was
covered. Unfortunately, though, if format_error/1 crashed
the compiler would catch the exception so that the test suite
would not notice it.

Add a smoke test of format_error/1 that will crash if there is
any problem with erl_lint:format_error/1.

Introduced when changing state from tuple to record.

* bjorn/cuddle-with-tests: (23 commits)
  rand_SUITE: Speed up basic_stats/1
  base64_SUITE: Speed up roundtrip/1
  lists_SUITE: Test lists:concat/2
  lists_SUITE: Test lists:split/2
  lists_SUITE: Add a test case for lists:prefix/2
  lists_SUITE: Add hof/1 to test all high-order functions
  lists_SUITE: Add test for lists:takewhile/1
  lists_SUITE: Run test cases in each group in parallel
  lists_SUITE: Test lists:keyreplace/4
  lists_SUITE: Extend flatten/1 test to also test flatlength/1
  lists_SUITE: Correct test of lists:flatten/2
  id_transform_SUITE: Modernize test suite
  io_proto_SUITE: Speed up determination of default shell
  io_proto_SUITE: Refactor up rtnode() and friends
  gen_event_SUITE: Remove unnecessary sleep calls
  proc_lib: Improve coverage for crash/1
  proc_lib_SUITE: Eliminate compiler warnings
  io_SUITE: Add coverage/1 to completely cover io_lib_pretty
  io_SUITE: Extend coverage of code for testing printable chars
  io_SUITE: Speed up test for bad +pc option
  ...

Refactor basic_stats/1 into three separate test cases that can be
run in parallel.

Refactor roundtrip/1 into 4 test cases that can be run in parallel.
Assuming that there are 4 cores available, the group of 4 test
cases will run at roughly one fourth of the time for the original
test case.