message: Fix IsSymLink on Linux
  IsSymlink was giving faulty results when finding recursive files on Linux. I've updated the function to use the built-in POSIX macro for checking if a file is a symlink.
diff: @@ -335,7 +335,7 @@ bool IsSymLink(const std::string& path) {
  struct stat buf;
  int result;
  result = lstat(path.c_str(), &buf);
  - return result == 0;
  + return S_ISLNK(buf.st_mode);
  }
  std::vector<std::string> GetPlatformClangArguments() {
  