ASM sources not correctly picking up iOS flags

[Naville]

As a result ASM objects are still built using native arch (missing -arch arm64 in compile flags)

[leetal]

I'll look into this in the coming days. We have not really had any need for ASM compilation so frankly, this is untested in this toolchain :(

[leetal]

I have now pushed some changes to the dev branch. Please test with that and see if that resolves your issues.