ggml : IQ4_NL sgemm + Q4_0 AVX optimization (#9422)
* squashed
readd my iq4_nl sgemm PR https://github.com/ggerganov/llama.cpp/pull/8049
have ggml_vec_dot_q4_0 do two blocks per loop for avx
try out f16c ggml_vec_dot_iq4_nl, but it's not really faster. as per https://github.com/ggerganov/llama.cpp/pull/8549 we can calculate several blocks at a time with no issue
* shuffle
* remove f16c iq4_nl as i cant make it faster than before
