cmake HAVE_ELF_H examples

Lewuathe/mlir-hello thirdparty/llvm-project/bolt/runtime/CMakeLists.txt :11 

check_include_files(elf.h HAVE_ELF_H)

google/glog CMakeLists.txt :129 

check_include_file_cxx (elf.h HAVE_ELF_H)

google/glog CMakeLists.txt :286 

endif (HAVE_ELF_H OR HAVE_SYS_EXEC_ELF_H)