cmake HAVE_LLVM_LIBCPP examples

google/mysql-protobuf configure.cmake :80 

CHECK_CXX_SOURCE_RUNS("
#include <ciso646>
int main()
{
#ifdef _LIBCPP_VERSION
  return 0;
#else
  return 1;
#endif
}" HAVE_LLVM_LIBCPP)

alibaba/AliSQL configure.cmake :97 

CHECK_CXX_SOURCE_RUNS("
#include <ciso646>
int main()
{
#ifdef _LIBCPP_VERSION
  return 0;
#else
  return 1;
#endif
}" HAVE_LLVM_LIBCPP)

mysql/mysql-shell configure.cmake :74 

CHECK_CXX_SOURCE_RUNS("
#include <ciso646>
int main()
{
#ifdef _LIBCPP_VERSION
  return 0;
#else
  return 1;
#endif
}" HAVE_LLVM_LIBCPP)

mongodb/mongo-bi-connector-odbc-driver configure.cmake :100 

CHECK_CXX_SOURCE_RUNS("
#include <ciso646>
int main()
{
#ifdef _LIBCPP_VERSION
  return 0;
#else
  return 1;
#endif
}" HAVE_LLVM_LIBCPP)