Get type parameter symbol through class definition

Author: nicolasstucki

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

@@ -112,7 +112,7 @@ class PCPCheckAndHeal(@constructorOnly ictx: Context) extends TreeMapWithStages(
           if (tp.isTerm)
             ctx.error(i"splice outside quotes", pos)
           tp
-        case tp: TypeRef if tp.prefix.derivesFrom(defn.QuotedTypeClass) && tp.name.toString == "T" =>
+        case tp: TypeRef if tp.symbol == defn.QuotedTypeClass.typeParams.head =>
           // Adapt direct references to the type of the type parameter T of a quoted.Type[T].
           // Replace it with a properly encoded type splice. This is the normal for expected for type splices.
           tp.prefix.select(tpnme.splice)