Fix remaining bugs in parallel GEMM3M

as suggested by hjmndv in #2370

add in runtime cpu detection for zarch

It used to be 5ms, which might not be long enough in some cases for the
thread to exit well, but then when set to 5000 (5s), it would slow down
any program depending on OpenBlas.

Let's just set it to 50ms, which is at least 10 times longer than
originally, but still reasonable in case of failed thread termination.

* Update DYNAMIC_ARCH list of ARM64 targets for gmake
* Update arm64 cpu list for runtime detection
* Update DYNAMIC_ARCH list of ARM64 targets for cmake and add POWERPC targets

was originally in #2228 but that PR had misplaced the file in the toplevel directory

Fix race conditions in multithreaded GEMM3M

from #2322

by adding barriers (and a mutex lock for the non-OpenMP case) like it was already done for GEMM in level3_thread.c some time ago

This patch was submitted to the GIMP project by a publisher wishing to
keep confidentiality (hence anonymously). I just pass along the patch.
Here is the patch explanation which came with:

First they remind us what Microsoft documentation says about
TerminateThread:
> TerminateThread is a dangerous function that should only be used in
> the most extreme cases. You should call TerminateThread only if you
> know exactly what the target thread is doing, and you control all of
> the code that the target thread could possibly be running at the time
> of the termination.
(https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-terminatethread)

Then they say that 5 milliseconds time-out might not be long enough for
the thread to exit gracefully. They propose to set it to a much higher
value (for instance here 5 seconds).

And finally you should always check the return value of
WaitForSingleObject(). In particular you want to run TerminateThread()
only if WaitForSingleObject() failed, not on success case.

1. qalloc() appears to have been a special routine written for the PPC440-based QCDOC supercomputer(s) from around 2005, its source does not seem to be readily available. So switch the #if 1 in the code to rely on standard malloc() by default.
2. Utility functions like get_num_procs, get_num_threads that were added to the "normally" used memory.c in the meantime were still missing here.

* Add automatic fixups for OSX/IOS cross-compilation

* Add OSX/IOS cross-compilation test to Travis CI

* Handle platforms that lack hwcap.h by falling back to ARMV8

* Fix PROLOGUE for OSX/IOS

This is similar to fixes in gh-1929, but there was one remaining
occurance of this type of pattern in the driver/level2/*_thread.c
files.

* Add gcc7-generated assembly files for POWER8/9 isa/ica-min/max and POWER9 caxpy

To work around internal compiler errors encountered when compiling the original C source with gcc 4 and 5, and wrong code generated by gcc 8.3.0

* Use gcc-generated assembly instead of original C sources

to work around internal compiler errors encountered with gcc 4.8/5.4 and wrong code generation by gcc 8.3

* Use gcc-generated assembly instead of the original C source

to work around internal compiler errors encountered with gcc 4.8 and 5.4, and wrong code generation by gcc 8.3

* Add gcc7-generated assembler version of caxpy for power8

to work around wrong code generated by gcc 8.3

* Handle CONJ define for caxpyc

* Handle CONJ define for caxpyc

* Add gcc7-generated assembly cdot for POWER9

* Use prebuilt assembly for POWER9 cdot

created with gcc 7.3.1 to work around ICE in older gcc versions

* Exclude POWER9 from DYNAMIC_ARCH when gcc versions is lower than 6

* Update Makefile.system

* Use PROLOGUE macro to ensure correct function name for DYNAMIC_ARCH

* Disable POWER9 with old gcc versions

Provide more information on mmap/munmap failure

for #2207

Do not try ancient PGI hacks with recent versions of that compiler

should fix #2139

Fix errors in cpu affinity setup with glibc 2.6

for #2114

Misc. typo fixes in comments and documentation

fixes #2104

Found via `codespell -q 3 -w -L ith,als,dum,nd,amin,nto,wis,ba -S ./relapack,./kernel,./lapack-netlib`

pool cleanup upon THREAD_DETACH which is needed when compiled with
USE_TLS=1.

Add CPUID data for Intel Denverton (as Nehalem)

Do not compile in AVX512 check if AVX support is disabled

xgetbv is function depends on NO_AVX being undefined - we could change that too, but that combo is unlikely to work anyway

Address warning in memory.c

Correct range limiting in trmv_thread and re-enable TRMV multithreading

Restore locking optimizations for OpenMP case

restore another accidentally dropped part of #1468 that was missed in #2004 to address performance regression reported in #1461

same bug as seen in #1388, somehow missed in corresponding PR #1389