Bug report and patch by Jeroen Demeyer.

* bpo-31310: multiprocessing's semaphore tracker should be launched again if crashed

* Avoid mucking with process state in test.
Add a warning if the semaphore process died, as semaphores may then be leaked.

* Add NEWS entry

* bpo-31308: If multiprocessing's forkserver dies, launch it again when necessary.

* Fix test on Windows

* Add NEWS entry

* Adopt a different approach: ignore SIGINT and SIGTERM, as in semaphore tracker.

* Fix comment

* Make sure the test doesn't muck with process state

* Also test previously-started processes

* Update 2017-08-30-17-59-36.bpo-31308.KbexyC.rst

* Avoid masking SIGTERM in forkserver.  It's not necessary and causes a race condition in test_many_processes.

When a single .c file contains several functions and/or methods with
the same name, a safety _METHODDEF #define statement is generated
only for one of them.

This fixes the bug by using the full name of the function to avoid
duplicates rather than just the name.

Support PYTHONPROFILEIMPORTTIME envvar equivalent to -X importtime

Add METH_STACKLESS to prevent future collisions.

* bpo-28643: Record profile-opt build progress with stamp files

The profile-opt makefile target is expensive to build. Since the
makefile does not contain complete dependency information for this
target, much extra work can get done if the build is interrupted and
re-started.  Even running "make" a second time will result in a huge
amount of redundant work.

As a minimal fix (rather than removing recursive "make" and adding a
proper dependency graph), split the profile-opt target into parts:

- ensure tree is clean (profile-clean-stamp)
- build with profile generation enabled (profile-gen-stamp)
- run task to generate profile information (profile-run-stamp)
- build optimized Python using above information (profile-opt)

We use "stamp" files to record completion of the steps.  Running
"make clean" will not remove the profile-run-stamp file.

Other minor changes:

- remove the "build_all_use_profile" target.  I don't expect callers
  of the makefile to use this target so that should be safe.

- remove execution of "profile-removal" at end of "profile-opt".  I
  don't see any reason to not to keep the profile information, given
  the cost to generate it.  Removing the "profile-run-stamp" file
  will force re-generation of it.

Add new time functions:

* time.clock_gettime_ns()
* time.clock_settime_ns()
* time.monotonic_ns()
* time.perf_counter_ns()
* time.process_time_ns()
* time.time_ns()

Add new _PyTime functions:

* _PyTime_FromTimespec()
* _PyTime_FromNanosecondsObject()
* _PyTime_FromTimeval()

Other changes:

* Add also os.times() tests to test_os.
* pytime_fromtimeval() and pytime_fromtimeval() now return
  _PyTime_MAX or _PyTime_MIN on overflow, rather than undefined
  behaviour
* _PyTime_FromNanoseconds() parameter type changes from long long to
  _PyTime_t

Add new clock identfiers:

* time.CLOCK_BOOTTIME
* time.CLOCK_PROF
* time.CLOCK_UPTIME

Skip a test for unget_wch()/get_wch() on OpenBSD since they are broken
in ncurses 5.7.

[asyncio] bpo-30423: add regression test for orphan future causes "RuntimeError: Event loop stopped before Future completed." (#3295)

* call remove_done_callback in finally section

* [asyncio] bpo-30423 bug: add regression test for orphan future causes "RuntimeError: Event loop stopped before Future completed."

Replace occurence of nested comments in blake2 reference implementation
with preprocessor directive for disabling unused code.

`blake2s-load-xop.h` is conditionally pulled in only on chips with XOP
support, among others the AMD Bulldozer. The malformed comments in the
source file breaks the build of `hashlib`'s `_blake2` on GCC 6.3.0.

Official reference code on github uses `#if` so this change should be
uncontroversial.

Modify the code to use ncurses is_pad() instead of checking WINDOW
_flags field.  If your platform does not provide the is_pad(), the
existing way that checks the field will be enabled.

Note: This change does not drop support for platforms where do not
have both WINDOW _flags field and is_pad().

bpo-31910: test_create_connection() now catchs also EADDRNOTAVAIL to
fix the test on Travis CI.

Cleanup pymalloc:

* Rename _PyObject_Alloc() to pymalloc_alloc()
* Rename _PyObject_FreeImpl() to pymalloc_free()
* Rename _PyObject_Realloc() to pymalloc_realloc()
* pymalloc_alloc() and pymalloc_realloc() don't fallback on the raw
  allocator anymore, it now must be done by the caller
* Add "success" and "failed" labels to pymalloc_alloc() and
  pymalloc_free()
* pymalloc_alloc() and pymalloc_free() don't update
  num_allocated_blocks anymore: it should be done in the caller
* _PyObject_Calloc() is now responsible to fill the memory block
  allocated by pymalloc with zeros
* Simplify pymalloc_alloc() prototype
* _PyObject_Realloc() now calls _PyObject_Malloc() rather than
  calling directly pymalloc_alloc()

_PyMem_DebugRawAlloc() and _PyMem_DebugRawRealloc():

* document the layout of a memory block
* don't increase the serial number if the allocation failed
* check for integer overflow before computing the total size
* add a 'data' variable to make the code easiler to follow

test_setallocators() of _testcapimodule.c now test also the context.

Document the following functions:

* PyObject_Malloc()
* PyObject_Calloc()
* PyObject_Realloc()
* PyObject_Free()

Fix also PyMem_RawFree() documentation.

* Fix a compilation error on FreeBSD.
* Fix the data attribute size on Mac OS X.

Write the name of each subtest on a new line to help debugging when
a test does crash Python.

bpo-31897: Convert unexpected errors when read bogus binary plists into InvalidFileException. (#4171)

Removed a code that incorrectly detected in-place resizing in realloc()
 and wrote to freed memory.

* Fixed the layout of the kqueue_event structure on OpenBSD and NetBSD.
* Fixed the comparison of the kqueue_event objects.

test_curses now saves/restores signals. On FreeBSD, the curses module
sets handlers of some signals, but don't restore old handlers when
the module is deinitialized.

Update the kwarg in the documentation of `multiprocessing.pool.Pool.starmap_async`, from `error_back` to `error_callback` to match the source code..

separators that are not bytes-like objects.

Editor and output windows only see an empty last prompt line.
This simplifies the code and fixes a minor bug when newline is inserted.
Sys.ps1, if present, is read on Shell start-up, but is not set or changed.

Changes persist while IDLE remains open

Use the _PyTime_t type rather than double for the faulthandler
timeout in dump_traceback_later().

This change should fix the following Coverity warning:

CID 1420311:  Incorrect expression  (UNINTENDED_INTEGER_DIVISION)
Dividing integer expressions "9223372036854775807LL" and "1000LL",
and then converting the integer quotient to type "double". Any
remainder, or fractional part of the quotient, is ignored.

    if ((timeout * 1e6) >= (double) PY_TIMEOUT_MAX) {

The warning comes from (double)PY_TIMEOUT_MAX with:

    #define PY_TIMEOUT_MAX (PY_LLONG_MAX / 1000)