ggml-cpu: aarm64: q5_K repack gemm and gemv (and generic) implementations (i8mm)...

ggml-cpu: aarm64: q5_K repack gemm and gemv (and generic) implementations (i8mm) (llama/18860)

* Boilerplate for q5_Kx8 REPACK on ARM and fallback

Signed-off-by: Alberto Cabrera <redacted>
* Implements make_block_q5_Kx8 by extending make_block_q4_Kx8

Signed-off-by: Alberto Cabrera <redacted>
* q5_K repack gemm and gemv generics

* Gemm and Gemv ARM implementations (i8mm)

* Improved qh manipulation looking at non-repack vec_dot implementation

* Full unroll

* Apply Q5_K Gemv vand and vshl optimizations to gemm. Improve comments.

Signed-off-by: Alberto Cabrera <redacted>
* Fix wrong fallback definitions of Q5_K

Signed-off-by: Alberto Cabrera <redacted>
* Fixed comments. Reverted unnecessary formatting

Signed-off-by: Alberto Cabrera <redacted>
* Fixed typo in generic definitions

* Switching AND + Shift with Shift Insert. Better op interleaving.

* Vectorize + unroll the block scales

* Apply gemm optimizations to gemv

* Improve bias calculation

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Signed-off-by: Alberto Cabrera <redacted>