chat: fix int overflow, prevent size calculation in float/double (ggm…

…l-org#17357)

* chat: fix int overflow, prevent size calculation in float/double

* Update common/chat.cpp

Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

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Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

ggml : add missing AVX512 feature checks (ggml-org#17270)

_mm512_cvtepu8_epi16        requires  __AVX512BW__
_mm512_srli_epi16           requires  __AVX512BW__
__builtin_ia32_inserti32x8  requires  __AVX512DQ__

Signed-off-by: Adrien Gallouët <angt@huggingface.co>

vulkan: Replace 16-bit unpack8 calls to work around legacy Windows AM…

…D driver bug (ggml-org#17285)