Revert special handling of Windows xNRM2 and enable C+intrinsics kern…

Minor CMAKE fixes

This is unlikely to happen in practice, but if it does, the rogue file would get included instead of the dynamically generated version for each target_core, leading to very confusing errors like "invalid operands (undefined UND and ABS sections)" in compilation of the assembly kernels as macros like PREFETCH would remain undefined

Optimize the performance of dot by using universal intrinsics in X86/ARM

Add bfloat16 based dot and conversion with single/double

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>

Make NO_AVX512 option override the AVX512 compile test in CMAKE builds as well

Work around ARMV8 build-time cpu detection problems on non-Linux systems

Enable new build target platform -- COOPERLAKE. This target platform
supports all the SKYLAKEX supported ISAs + avx512bf16. So all the
SKYLAKEX specific kernels/drivers and related code are now extended
to be also active on COOPERLAKE. Besides, new BF16 related kernels
are active under this target.

Adjust A53 SGEMM parameters to reflect recent switch to 8x8 kernel

powerpc: Add support for future processor

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

Add CMAKE support for MAX_STACK_ALLOC setting

* make building the bfloat16 BLAS functions conditional on BUILD_HALF

* pass the BUILD_HALF option to gensymbol

* Pass BUILD_HALF as a compiler define for dynamic_arch builds

Supports ifeq and ifneq, but requires both to have an else branch