Apply suggestions from code review

Co-Authored-By: Mazdak Farrokhzad <twingoow@gmail.com>

Author: matthewjasper

src/librustc_mir_build/build/matches/mod.rs

@@ -840,10 +840,10 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     ///     (false, true) => (),
     /// }
     ///
-    /// For this match we check if `x.0` matches `true` (for the first
-    /// arm) if that's false we check `x.1`, if it's `true` we check if
+    /// For this match, we check if `x.0` matches `true` (for the first
+    /// arm). If that's false, we check `x.1`. If it's `true` we check if
     /// `x.0` matches `false` (for the third arm). In the (impossible at
-    /// runtime) case when `x.0` is now `true` we branch to
+    /// runtime) case when `x.0` is now `true`, we branch to
     /// `otherwise_block`.
     fn match_candidates<'pat>(
         &mut self,
@@ -1104,6 +1104,8 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
     ) {
         let (first_candidate, remaining_candidates) = candidates.split_first_mut().unwrap();
 
+        // All of the or-patterns have been sorted to the end, so if the first
+        // pattern is an or-pattern we only have or-patterns.
         match *first_candidate.match_pairs[0].pattern.kind {
             PatKind::Or { .. } => (),
             _ => {

src/test/ui/or-patterns/basic-switchint.rs

@@ -26,9 +26,6 @@ fn test_foo(x: Foo) -> MatchArm {
         // multiple or-patterns for one structure.
         Foo::Two(42 | 255, 1024 | 2048) => MatchArm::Arm(2),
         // mix of pattern types in one or-pattern (range).
-        //
-        // FIXME(dlrobertson | Nadrieril): Fix or-pattern completeness and
-        // unreachabilitychecks for ranges.
         Foo::One(100 | 110..=120 | 210..=220) => MatchArm::Arm(3),
         // multiple or-patterns with wild.
         Foo::Two(0..=10 | 100..=110, 0 | _) => MatchArm::Arm(4),