cmake HAVE_CEILF examples

GenericMappingTools/gmt cmake/modules/ConfigureChecks.cmake :393 

check_symbol_exists (ceilf       "${_math_h}" HAVE_CEILF)

llvm-dcpu16/llvm-dcpu16 cmake/config-ix.cmake :105 

check_symbol_exists(ceilf math.h HAVE_CEILF)

KhronosGroup/SPIRV-LLVM cmake/config-ix.cmake :142 

check_symbol_exists(ceilf math.h HAVE_CEILF)