cmake CLANG_HAVE_DLADDR examples

Lewuathe/mlir-hello thirdparty/llvm-project/clang/CMakeLists.txt :193 

check_symbol_exists(dladdr dlfcn.h CLANG_HAVE_DLADDR)

root-project/root interpreter/llvm-project/clang/CMakeLists.txt :180 

check_symbol_exists(dladdr dlfcn.h CLANG_HAVE_DLADDR)