MIR dump: restructure pretty to be more extensible by other code

Author: nikomatsakis

src/librustc_mir/borrow_check/nll/mod.rs

@@ -170,14 +170,15 @@ fn dump_mir_results<'a, 'gcx, 'tcx>(
                 writeln!(out, "    | Live variables on entry to {:?}: {}", bb, s)?;
             }
 
-            PassWhere::InCFG(location) => {
+            PassWhere::BeforeLocation(location) => {
                 let s = live_variable_set(
                     &regular_liveness_per_location[&location],
                     &drop_liveness_per_location[&location],
                 );
                 writeln!(out, "            | Live variables at {:?}: {}", location, s)?;
             }
 
+            PassWhere::AfterLocation(_) |
             PassWhere::AfterCFG => {}
         }
         Ok(())

src/librustc_mir/lib.rs

@@ -18,12 +18,15 @@ Rust MIR: a lowered representation of Rust. Also: an experiment!
 
 #![feature(box_patterns)]
 #![feature(box_syntax)]
+#![feature(catch_expr)]
 #![feature(conservative_impl_trait)]
 #![feature(const_fn)]
 #![feature(core_intrinsics)]
 #![feature(decl_macro)]
 #![feature(i128_type)]
+#![feature(inclusive_range_syntax)]
 #![feature(match_default_bindings)]
+#![feature(range_contains)]
 #![feature(rustc_diagnostic_macros)]
 #![feature(placement_in_syntax)]
 #![feature(collection_placement)]

src/librustc_mir/util/mod.rs

@@ -15,7 +15,7 @@ pub mod patch;
 
 mod alignment;
 mod graphviz;
-mod pretty;
+pub(crate) mod pretty;
 pub mod liveness;
 
 pub use self::alignment::is_disaligned;