cmake LIBCXX_HAS_PTHREAD_LIB examples

Lewuathe/mlir-hello thirdparty/llvm-project/libcxx/cmake/config-ix.cmake :130 

check_library_exists(pthread pthread_create "" LIBCXX_HAS_PTHREAD_LIB)

PlatONnetwork/pWASM libc++/libcxx/cmake/config-ix.cmake :84 

check_library_exists(pthread pthread_create "" LIBCXX_HAS_PTHREAD_LIB)

CTSRD-CHERI/cheribsd contrib/subrepo-cheri-libc++/cmake/config-ix.cmake :128 

check_library_exists(pthread pthread_create "" LIBCXX_HAS_PTHREAD_LIB)