Enable xgot feature for mips64 musl targets

This was missed in b65c2af, 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.

Signed-off-by: Jens Reidel <[email protected]>

Author: Gelbpunkt

compiler/rustc_target/src/spec/targets/mips64_unknown_linux_muslabi64.rs

@@ -5,7 +5,7 @@ use crate::spec::{Target, TargetMetadata, TargetOptions, base};
 pub(crate) fn target() -> Target {
     let mut base = base::linux_musl::opts();
     base.cpu = "mips64r2".into();
-    base.features = "+mips64r2".into();
+    base.features = "+mips64r2,+xgot".into();
     base.max_atomic_width = Some(64);
     Target {
         // LLVM doesn't recognize "muslabi64" yet.

compiler/rustc_target/src/spec/targets/mips64el_unknown_linux_muslabi64.rs

@@ -3,7 +3,7 @@ use crate::spec::{Target, TargetMetadata, TargetOptions, base};
 pub(crate) fn target() -> Target {
     let mut base = base::linux_musl::opts();
     base.cpu = "mips64r2".into();
-    base.features = "+mips64r2".into();
+    base.features = "+mips64r2,+xgot".into();
     base.max_atomic_width = Some(64);
     // FIXME(compiler-team#422): musl targets should be dynamically linked by default.
     base.crt_static_default = true;