Remove box syntax from rustc_infer

compiler/rustc_infer/src/infer/equate.rs

@@ -105,7 +105,7 @@ fn regions(
         b: ty::Region<'tcx>,
     ) -> RelateResult<'tcx, ty::Region<'tcx>> {
         debug!("{}.regions({:?}, {:?})", self.tag(), a, b);
-        let origin = Subtype(box self.fields.trace.clone());
+        let origin = Subtype(Box::new(self.fields.trace.clone()));
         self.fields
             .infcx
             .inner

compiler/rustc_infer/src/infer/glb.rs

@@ -67,7 +67,7 @@ fn regions(
     ) -> RelateResult<'tcx, ty::Region<'tcx>> {
         debug!("{}.regions({:?}, {:?})", self.tag(), a, b);
 
-        let origin = Subtype(box self.fields.trace.clone());
+        let origin = Subtype(Box::new(self.fields.trace.clone()));
         Ok(self.fields.infcx.inner.borrow_mut().unwrap_region_constraints().glb_regions(
             self.tcx(),
             origin,

compiler/rustc_infer/src/infer/lub.rs

@@ -67,7 +67,7 @@ fn regions(
     ) -> RelateResult<'tcx, ty::Region<'tcx>> {
         debug!("{}.regions({:?}, {:?})", self.tag(), a, b);
 
-        let origin = Subtype(box self.fields.trace.clone());
+        let origin = Subtype(Box::new(self.fields.trace.clone()));
         Ok(self.fields.infcx.inner.borrow_mut().unwrap_region_constraints().lub_regions(
             self.tcx(),
             origin,

compiler/rustc_infer/src/infer/sub.rs

@@ -142,7 +142,7 @@ fn regions(
         // FIXME -- we have more fine-grained information available
         // from the "cause" field, we could perhaps give more tailored
         // error messages.
-        let origin = SubregionOrigin::Subtype(box self.fields.trace.clone());
+        let origin = SubregionOrigin::Subtype(Box::new(self.fields.trace.clone()));
         self.fields
             .infcx
             .inner

compiler/rustc_infer/src/lib.rs

@@ -15,7 +15,6 @@
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(bool_to_option)]
 #![feature(box_patterns)]
-#![feature(box_syntax)]
 #![feature(extend_one)]
 #![feature(iter_zip)]
 #![feature(never_type)]