std_detect: add avx512fp16 #1959

Job	Run time
Check Style	14s
Env Override	12s
Build std_detect	1m 0s
Build Documentation	1m 4s
Automatic intrinsic verification	26s
Test (i686-unknown-linux-gnu)	2m 5s
Test (x86_64-unknown-linux-gnu)	3m 35s
Test (x86_64-unknown-linux-gnu-emulated)	9m 23s
Test (arm-unknown-linux-gnueabihf)	1m 25s
Test (armv7-unknown-linux-gnueabihf)	10m 47s
Test (aarch64-unknown-linux-gnu)	21m 33s
Test (riscv64gc-unknown-linux-gnu)	1m 14s
Test (powerpc64le-unknown-linux-gnu)	3m 36s
Test (s390x-unknown-linux-gnu)	1m 17s
Test (wasm32-wasi)	1m 29s
Test (i586-unknown-linux-gnu)	1m 56s
Test (nvptx64-nvidia-cuda)	29s
Test (thumbv6m-none-eabi)	14s
Test (thumbv7m-none-eabi)	17s
Test (thumbv7em-none-eabi)	17s
Test (thumbv7em-none-eabihf)	15s
Test (aarch64-apple-darwin)	1m 30s
Test (x86_64-pc-windows-msvc)	6m 12s
Test (i686-pc-windows-msvc)	2m 46s
Test (x86_64-apple-darwin, macos-11)	7m 20s
success	1s
	1h 20m 37s

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