cmake HAVE_ISINF_IN_MATH_H examples

llvm-dcpu16/llvm-dcpu16 cmake/config-ix.cmake :101 

check_symbol_exists(isinf math.h HAVE_ISINF_IN_MATH_H)

KhronosGroup/SPIRV-LLVM cmake/config-ix.cmake :138 

check_symbol_exists(isinf math.h HAVE_ISINF_IN_MATH_H)