LoongArch64: Update dgemm kernel

Apply USE_TRMM to MIPS64_GENERIC as to GENERIC in gmake builds

LoongArch64: Add dgemv_t_8_lasx.S and dgemv_n_8_lasx.S

Enable use of AVX512 microkernels with NVIDIA HPC from version 22.3

Use SVE zgemm/cgemm on Arm(R) Neoverse(TM) V1 core

This patch removes the prefetches from cgemm/zgemm which improves the performance similar to sgemm/dgemm did in #3868, this means I'm happy to enable this on any applicable cores.

I also replicated the unrolling the copies from sgemm and dgemm.

Whilst disambiguating whilelt, I inadvertantly used the wrong datatype
for offsets, which can be negative. This rectifies that.

Use latest non-SVE kernels in ARMV8SVE

These are generally better and, in some cases, include threading which helps in the cores we're targeting here.

Restore zero-initialization of variables in generic ztrsm_utcopy

* Add AppleClang crossbuild to MacOS/arm64 DYNAMIC_ARCH

* add casts to disambiguate svwhilelt for clang

Sapphire Rapids sbgemm fix

This patch removes the warning messages related to unused variables in
sbgemm_kernel_power10.c.

Signed-off-by: Manjul Mohan <manjul@linux.vnet.ibm.com>

[WIP] Disable gcc's tree-vectorizer for x86_64 CGEMV