Update compiler/rustc_borrowck/src/eliminate_placeholders.rs

Co-authored-by: lcnr <[email protected]>

Author: amandasystems

compiler/rustc_borrowck/src/eliminate_placeholders.rs

@@ -115,7 +115,8 @@ impl RegionTracker {
     }
 
     /// Returns `true` if during the annotated SCC reaches a placeholder
-    /// with a universe larger than the smallest reachable one, `false` otherwise.
+    /// with a universe larger than the smallest nameable universe of any
+    /// reachable existential region.
     pub(crate) fn has_incompatible_universes(&self) -> bool {
         self.max_nameable_universe().cannot_name(self.max_placeholder_universe_reached)
     }