Is endianness relevant?

[msrd0]

I should test the Argb struct and Rgba struct on platform with different endianness from linux to verify it works. For now, we emit a warning from a build script if we detect big endianness.

[msrd0]

Those have been replaced with rgb::BGRA8 and rgb::RGBA8, respectively. However, the problem with endianness remains, and I still have no big endian hardware to test on.