Fix criterion when value classes have user defined equals methods

Author: odersky

compiler/src/dotty/tools/dotc/transform/VCElideAllocations.scala

@@ -3,7 +3,7 @@ package transform
 
 import ast.tpd
 import core._
-import Contexts._, Symbols._, Types._, Flags._
+import Contexts._, Symbols._, Types._, Flags._, Phases._
 import DenotTransformers._, MegaPhase._
 import TreeExtractors._, ValueClasses._
 
@@ -24,8 +24,10 @@ class VCElideAllocations extends MiniPhase with IdentityDenotTransformer {
 
   override def transformApply(tree: Apply)(using Context): Tree =
     def hasUserDefinedEquals(tp: Type): Boolean =
-      val eql = defn.Any_equals.overridingSymbol(tp.typeSymbol.asClass)
-      eql.exists && !eql.is(Synthetic)
+      val eql = atPhase(erasurePhase) {
+        defn.Any_equals.matchingMember(tp.typeSymbol.thisType)
+      }
+      eql.owner != defn.AnyClass && !eql.is(Synthetic)
     tree match {
       // new V(u1) == new V(u2) => u1 == u2, unless V defines its own equals.
       // (We don't handle != because it has been eliminated by InterceptedMethods)