d8c093be2c
Enable xgot feature for mips64 musl targets
This was missed in b65c2afdfd, which only enabled it for the glibc targets.
I didn't feel comfortable touching the OpenWRT target, whoever maintains that will probably want to take a look whether it is necessary there as well.
rustc_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.