Add tracking issue for MIPS intrinsics

Author: Amanieu

crates/core_arch/src/mips/mod.rs

@@ -5,6 +5,7 @@
 #[cfg(target_feature = "fp64")]
 mod msa;
 #[cfg(target_feature = "fp64")]
+#[unstable(feature = "stdarch_mips", issue = "111198")]
 pub use self::msa::*;
 
 #[cfg(test)]
@@ -13,6 +14,7 @@ use stdarch_test::assert_instr;
 /// Generates the trap instruction `BREAK`
 #[cfg_attr(test, assert_instr(break))]
 #[inline]
+#[unstable(feature = "stdarch_mips", issue = "111198")]
 pub unsafe fn break_() -> ! {
     crate::intrinsics::abort()
 }