02840ca8ab
Specifically, remove both `-Z no_integrated_as` and `TargetOptions::no_integrated_as`. The latter was only used for the `msp430_none_elf` platform, for which it's no longer required.
librustc_target contains some very low-level details that are
specific to different compilation targets and so forth.
For more information about how rustc works, see the rustc dev guide.