message: Don't compile the dotprod path outside of Linux,
  we don't know non-Linux devices with dotprod and we don't know
  yet dotprod-runtime-detection code that runs outside of Linux.
diff: @@ -98,9 +98,14 @@ inline Path GetMostSignificantPath(Path path_mask) {
  // ruy::kAllPaths represents all Path's that make sense to on a given
  // base architecture.
  #ifdef __aarch64__
  +#ifdef __linux__
  constexpr Path kAllPaths =
  Path::kReference | Path::kStandardCpp | Path::kNeon | Path::kNeonDotprod;
  #else
  +// We don't know how to do runtime dotprod detection outside of linux for now.
  +constexpr Path kAllPaths = Path::kReference | Path::kStandardCpp | Path::kNeon;
  +#endif
  +#else
  constexpr Path kAllPaths = Path::kReference | Path::kStandardCpp;
  #endif
  