Rename arch::x86 to arch::i686.
When using fzf to open files, it's better not for a much less used arch, x86, to be the prefix of the main redox kernel arch, x86_64. We could possibly additionally add an x86 module for code shared between x86_64 and i686 later.
Also clears DF when entering from interrupts, on i686.
Edited by Jacob Lorentzon