Several people have requested that the assert macros in EUnit should be
moved out to a separate header file. This patch puts them in
stdlib/include/assert.hrl, which gets included by the eunit.hrl file.
Thus, nothing changes for eunit users, but the asserts can now also be
included separately.

* dgud/stdlib/rand/OTP-12586:
  stdlib: Document and add normal distributed random value function
  stdlib: Add new random functionality/module

As the erl_anno module is used by the compiler, it must be included
in the set of modules that are used when building the primary
bootstrap.

Introduce erl_anno, an abstraction of the second element of tokens and
tuples in the abstract format. The convention that negative line
numbers can be used for silencing compiler warnings will no longer
work in OTP 19; instead the annotation 'generated' is to be used.

The old random module contains an old algorithm which have flaws
and the api requires the user to invoke seed and or checking if seed have
been invoked, if a non constant seed is to be used.

The api contains the following features:
- The user can invoke rand:unform/[0|1] directly and get a non constant seeding.
- The api is split in functional and non functional functions,
  i.e. usage of _s functions will not affect the process dictionary.
- The api contains several algorithms with different characteristics and
  can be extended with new algorithms in the future.
- Contains state of the art random number generators.
- Default algorithm is taylor made for erlang to be fast on 64bits machines.

This module has been marked experimental for more than 15 years,
and has largely been superseded by the pg2 module from the kernel
application. The original pg also has no tests and has not been
updated in the last 15 years other than small maintenance edits
(like adding specs or replacing pid/1 by is_pid/1). It is pretty
unlikely that anyone uses it today and its presence is simply
confusing as people should be using pg2 anyway.

Name conforms to EEP.

The map type is set to term.