Update universal_regions.rs

compiler/rustc_borrowck/src/universal_regions.rs

@@ -162,7 +162,7 @@ struct UniversalRegionIndices<'tcx> {
     /// `ty::Region` to the internal `RegionVid` we are using. This is
     /// used because trait matching and type-checking will feed us
     /// region constraints that reference those regions and we need to
-    /// be able to map them our internal `RegionVid`. This is
+    /// be able to map them to our internal `RegionVid`. This is
     /// basically equivalent to an `InternalSubsts`, except that it also
     /// contains an entry for `ReStatic` -- it might be nice to just
     /// use a substs, and then handle `ReStatic` another way.