Fix typo in common.h

When Intel CET is enabled, we need to include <cet.h> in assembly codes
to mark Intel CET support and place _CET_ENDBR at the function entry.

1. Added bfloat16 based dot as new API: shdot
2. Implemented generic kernel and cooperlake-specific (AVX512-BF16) kernel for shdot
3. Added 4 conversion APIs for bfloat16 data type <=> single/double: shstobf16 shdtobf16 sbf16tos dbf16tod
     shstobf16 -- convert single float array to bfloat16 array
     shdtobf16 -- convert double float array to bfloat16 array
     sbf16tos  -- convert bfloat16 array to single float array
     dbf16tod  -- convert bfloat16 array to double float array
4. Implemented generic kernels for all 4 conversion APIs, and cooperlake-specific kernel for shstobf16 and shdtobf16
5. Update level1 thread facilitate functions and macros to support multi-threading for these new APIs
6. Fix Cooperlake platform detection/specify issue when under dynamic-arch building
7. Change the typedef of bfloat16 from unsigned short to more strict uint16_t

Signed-off-by: Chen, Guobing <guobing.chen@intel.com>

This is the initial patch to support build infrastructure
for POWER10 architecture.

This patch adds support for bfloat16 data type matrix multiplication kernel.
For architectures that don't support bfloat16, it is defined as unsigned short
(2 bytes).  Default unroll sizes can be changed as per architecture as done for
SGEMM and for now 8 and 4 are used for M and N.  Size of ncopy/tcopy can be
changed as per architecture requirement and for now, size 2 is used.

Added shgemm in kernel/power/KERNEL.POWER9 and tested in powerpc64le and
powerpc64.  For reference, added a small test compare_sgemm_shgemm.c to compare
sgemm and shgemm output.

This patch does not cover OpenBLAS test, benchmark and lapack tests for shgemm.
Complex type implementation can be discussed and added once this is approved.

for calling from concurrent threads

The Windows-native GetEnvironmentVariable cannot be relied on, as
Cygwin does not always copy environment variables set through Cygwin
to the Windows environment block, particularly after fork().

Bugfix in #1713 for Windows (LLP64), where `blasabs` needs to be `llabs` rather than `labs` for the 64-bit API.

Introduce blasabs macro and use it to switch between abs and labs for INTERFACE64

sched_yield only burns cpu cycles, fixes #900,  see also #923, #1560

see #1593

fixes #1593

Change-Id: Ic896276cd073d6b41930c7c5a29d66348cd1725d

With this change, OpenBLAS builds and all tests pass on OpenBSD 6.2
using Clang. Tested on x86-64 only, with and without DYNAMIC_ARCH=1.

Conflicts:
	CONTRIBUTORS.md

MSVC treats the declaration of omp_in_parallel and omp_get_num_procs without the modifiers __declspec(dllimport) and __cdecl as a redefinition.