- Adds bgemv T based off of sbgemv T kernel
- Adds bgemv N which is slightly alterated to not use Y as an
accumulator due to the output being bf16 which results in loss of
precision
- Enables BGEMM_GEMV_FORWARD to proxy BGEMM to BGEMV with new kernels

This also improves the testing and generic kernel by re-using the BF16
conversion functions.

Built on top of https://github.com/OpenMathLib/OpenBLAS/pull/5357 and derived from https://github.com/OpenMathLib/OpenBLAS/pull/5287

Co-authored-by: Ye Tao <ye.tao@arm.com>

Added HFLOAT16 support for RISCV64
Added shgemm_kernel_8x8 for RISCV64_ZVL128B and shgemm_kernel_16x8 for RISCV64_ZVL256B based on HFLOAT16
The instruction sets used are ZVFH and ZFH, which need to be supported by RVV1.0

Related to issue #5279
Co-authored-by Linjin Li <linjin_li@163.com>

In https://github.com/OpenMathLib/OpenBLAS/issues/4776
we're hitting
** On entry to SLASCL parameter number  4 had an illegal value

on codspeed, but not outside (either locally or on github runners)

No interface named {c/z}a{min/max}, keeping it would
cause ambiguity

This re-spins #3869 with some additional copy unrolling which helps maintain SYRK performance.

After #3868, the SVE kernels represent a pretty good boost.

This re-uses ARMV8SVE as a base and I'm going to incrementally move everything to use ARMV8SVE in additional patches (as well as fix up anything that's not already in ARMV8SVE).

Removing y avoids cache effects (if y is the size of the L1 cache, the
main array x is removed from it).
Moving init and timing out of the loop makes the scal benchmark behave like
the gemm benchmark, and allows higher accuracy for smaller test cases since
the loop overhead is much smaller than the timing overhead.

Example:
OPENBLAS_LOOPS=10000 ./dscal.goto 1024 8192 1024
on AMD Zen2 (7532) with 32k (4k doubles) L1 cache per core.

Before
From : 1024  To : 8192 Step = 1024 Inc_x = 1 Inc_y = 1 Loops = 10000
   SIZE       Flops
   1024 :     5627.08 MFlops   0.000000 sec
   2048 :     5907.34 MFlops   0.000000 sec
   3072 :     5553.30 MFlops   0.000001 sec
   4096 :     5446.38 MFlops   0.000001 sec
   5120 :     5504.61 MFlops   0.000001 sec
   6144 :     5501.80 MFlops   0.000001 sec
   7168 :     5547.43 MFlops   0.000001 sec
   8192 :     5548.46 MFlops   0.000001 sec

After
From : 1024  To : 8192 Step = 1024 Inc_x = 1 Inc_y = 1 Loops = 10000
   SIZE       Flops
   1024 :     6310.28 MFlops   0.000000 sec
   2048 :     6396.29 MFlops   0.000000 sec
   3072 :     6439.14 MFlops   0.000000 sec
   4096 :     6327.14 MFlops   0.000001 sec
   5120 :     5628.24 MFlops   0.000001 sec
   6144 :     5616.41 MFlops   0.000001 sec
   7168 :     5553.13 MFlops   0.000001 sec
   8192 :     5600.88 MFlops   0.000001 sec

We can see the L1->L2 switchover point is now where it should be, and the
number of flops for L1 is more accurate.

It stores the pointer, not an offset (that would be an alternative approach).

Benchmarks should allocate with cacheline (often 64 bytes) alignment
to avoid unreliable timings. This technique, storing the offset in the
byte before the pointer, doesn't require C11's aligned_alloc for
compatibility with older compilers.

For example, Glibc's x86_64 malloc returns 16-byte aligned buffers, which is
not sufficient for AVX/AVX2 (32-byte preferred) or AVX512 (64-byte).

Fixes #3439

Add lower limit for multithreading in xSYRK

to fix linking problems with (at least) the AMD version of flang that creates dependencies on more than just the fortran runtime.

This patch is to enable benchtest for half precision gemm
when BUILD_HALF is set during make.

[description]: when the matrix size goes higher than 5800 during the cpotrf test, error info, such as "Potrf info = 5679", will be returned on ARM64 and x86 machines. Uplo = L & F.
[solution]: changed the func for building the matrix so that the complex Hermitian matrix can stay positive definite during the computation.
[dts]:

[OpenBLAS]: benchmark for her/her2 LEVEL2 functions