message: fix a linker warning
diff: @@ -420,7 +420,7 @@ constexpr inline MTLCompareFunction getCompareFunction(SamplerCompareFunc compar
  }
  API_AVAILABLE(macos(10.15), ios(13.0))
  -MTLTextureSwizzle getSwizzle(TextureSwizzle swizzle) {
  +constexpr inline MTLTextureSwizzle getSwizzle(TextureSwizzle swizzle) {
  switch (swizzle) {
  case TextureSwizzle::SUBSTITUTE_ZERO:
  return MTLTextureSwizzleZero;
  @@ -438,7 +438,7 @@ MTLTextureSwizzle getSwizzle(TextureSwizzle swizzle) {
  }
  API_AVAILABLE(macos(10.15), ios(13.0))
  -MTLTextureSwizzleChannels getSwizzleChannels(TextureSwizzle r, TextureSwizzle g, TextureSwizzle b,
  +inline MTLTextureSwizzleChannels getSwizzleChannels(TextureSwizzle r, TextureSwizzle g, TextureSwizzle b,
  TextureSwizzle a) {
  return MTLTextureSwizzleChannelsMake(getSwizzle(r), getSwizzle(g), getSwizzle(b),
  getSwizzle(a));
  