cmake HAVE_SIZET examples

zju-abclab/NEXUS thirdparty/SEAL-4.1-bs/CMakeLists.txt :519 

unset(HAVE_SIZET CACHE)

zju-abclab/NEXUS thirdparty/SEAL-4.1-bs/CMakeLists.txt :523 

unset(HAVE_SIZET CACHE)