erts: Move compiler flags generation

Move the call to utils/make_compiler_flags to after _create_dirs
to make sure that the dirs are created before we try to generate files
in there. This seems to work with parallel make as well, but I cannot
find any documentation that says that it should or should not work.
erts: Fix resolve of generated files for depend
Support maps in cover
Handle nonempty list types in docgen_edoc_xml_cb
Handle map types in docgen_edoc_xml_cb
Substitude uses of lists:reverse(L1) ++ L2 with lists:reverse(L1, L2)
Introduce and use a hipe_icode:icode() type
Add specs for exported functions (to shut off a warning) and types in some record fields
Cleanup and make sure warnings are treated as errors
Disable accidentally enabled floating point exceptions on MacOS X

In c7ddafbe, which disabled floating point exceptions on Linux,
floating point exceptions were accidentally enabled on MacOS X.
Let xcomp/README.md refer to HOWTO/INSTALL-CROSS.md
Update preloaded and primary bootstrap
Merge branch 'bjorn/erts/fp-exceptions-on-osx'

* bjorn/erts/fp-exceptions-on-osx:
  Disable accidentally enabled floating point exceptions on MacOS X
Merge branch 'rickard/xcomp-readme'

* rickard/xcomp-readme:
  Let xcomp/README.md refer to HOWTO/INSTALL-CROSS.md
erts: Fix Map cmp exact equal of an empty map

The expression,

  #{} =:= M

where M was any Map, would always result in 'true'.

This commit fixes this issue by first comparing sizes for
both terms and then checking for size zero.
hipe: Break apart hipe_bif:make_fe/3 into two BIFs

This commit is a preparation for eliminating a race condition
loading the native code for modules whose BEAM code has already
been loaded. Here we introduce two new BIFs so that looking up
a fun entry is separate from setting the native address in the
fun entry.
Delay patching of closures to eliminate a race condition

The loader of native code tries to avoid race condition by bringing
down the system to a single scheduler. Unfortunately, that will not
completely avoid race conditions beacuse other processes may still
run while the code is being loaded. Therefore, we must still make
sure that native code has been fully fixed up before it can be
executed.

Under unlucky circumstances, it was possible for the global name
register process to call a fun in native code before the native
code for the fun had been fully fixed up. The run-time system
would crash when running the not-fully-fixed-up code.

Here is a way to make the bug 100% reproducible. First add this
function to the 'global' module:

silly_looper(List) ->
    lists:foreach(fun(E) -> put(any_atom, E) end, List),
    silly_looper(List).

Then insert the following code at the beginning of the init/1
function in the 'global' module:

    spawn_link(fun() -> silly_looper(lists:seq(1, 100)) end),

The run-time system will crash during start up when the native
code for the 'global' module is being loaded. What will happen
is that lists:foreach/2 (which runs in native code) will call
the native code for the fun in silly_looper/1 before the reference
to 'any_atom' has been changed from a 0 to the proper tagged
atom value. The put/2 BIF will exit when attempting to calculate
the hash value for the illegal value 0 (it is not properly tagged).

To eliminate this race condition, we must delay patching the
native code addresses for a fun into the fun entry until the native
code has been fully fixed up. We will use the new BIFs introduced
in the previous commit.

While we are at it, we will also make sure that we erase any
temporary variables in the process dictionary used by the
hipe_unified_loader module.
compiler: Fix error message printout on compile error

Use correct stack in printout.
erts: Fix leak in nif_SUITE:resource_takeover (again)
erts: Suppress false leak in hipe_thread_signal_init