Use a hash table header and SIMD to speed up hash table operations (similar to [Swiss Tables](https://abseil.io/about/design/swisstables)). #668

Job	Run time
Build and test cmake:gcc9	31s
Build and test cmake:clang15	42s
Build and test cmake:clang15:asan	55s
Build and test cmake:clang15:tsan	48s
Build and test cmake:clang15:ubsan	1m 9s
Build and test cmake:qemu-arm-neon-gcc	23s
Build and test cmake-osx:clang	40s
Build and test cmake-osx:gcc	42s
Build and test cmake-win64:msvc-rel	1m 3s
Build and test cmake-win64:msvc-dbg	1m 3s
Build and test fuzz:clang15	26s
Build and test python3.10:clang15	1m 11s
Build and test python3.10-win	41s
Build and test maven	38s
Build and test bazel:root	27s
Build and test bazel:go	31s
Build and test bazel:java	1m 4s
Build and test bazel:research	27s
Build and test bazel-osx:root	1m 5s
Build and test bazel-osx:go	1m 13s
Build and test bazel-osx:java	1m 42s
Build and test bazel-osx:research	59s
Build and test bazel-win:root	1m 4s
Build and test bazel-win:java	1m 6s
Build and test bazel-win:research	1m 3s
	21m 33s

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