GADT: Use isPatternBound, ofc...

Author: dwijnand

compiler/src/dotty/tools/dotc/core/GadtConstraint.scala

@@ -83,7 +83,7 @@ class GadtConstraint private (
           // B$2 had info <: B$1 and fullBounds <: B$1
           // We can use the info of B$2 to drop the lower-bound of B$1
           // and return non-bidirectional bounds B$1 <: X and B$2 <: B$1.
-          if tp.name.is(UniqueName) && !tp.info.hiBound.isExactlyAny && self <:< tp.info.hiBound => acc
+          if tp.symbol.isPatternBound && !tp.info.hiBound.isExactlyAny && self <:< tp.info.hiBound => acc
         case tp => acc | tp
     }
 
@@ -92,7 +92,7 @@ class GadtConstraint private (
     constraint.minUpper(param).foldLeft(nonParamBounds(param).hi) { (acc, u) =>
       externalize(u) match
         case tp: TypeRef // same as fullLowerBounds
-          if tp.name.is(UniqueName) && !tp.info.loBound.isExactlyNothing && tp.info.loBound <:< self => acc
+          if tp.symbol.isPatternBound && !tp.info.loBound.isExactlyNothing && tp.info.loBound <:< self => acc
         case tp =>
           // Any as the upper bound means "no bound", but if F is higher-kinded,
           // Any & F = F[_]; this is wrong for us so we need to short-circuit