Check the extended control register to see if AVX is actually usable
Check the extended control register to see if AVX is actually usable

pmienk/libsodium,rustyhorde/libsodium,Payshares/libsodium,pmienk/libsodium,eburkitt/libsodium,Payshares/libsodium,eburkitt/libsodium,eburkitt/libsodium,rustyhorde/libsodium,rustyhorde/libsodium,pmienk/libsodium,rustyhorde/libsodium,Payshares/libsodium