Normalize tuple types in synthetized classOf instances

Author: mbovel

compiler/src/dotty/tools/dotc/typer/Synthesizer.scala

@@ -53,7 +53,7 @@ class Synthesizer(typer: Typer)(using @constructorOnly c: Context):
             if defn.SpecialClassTagClasses.contains(sym) then
               classTagModul.select(sym.name.toTermName).withSpan(span)
             else
-              val ctype = escapeJavaArray(erasure(tp))
+              val ctype = escapeJavaArray(erasure(tp.normalizedTupleType))
               if ctype.exists then
                 classTagModul.select(nme.apply)
                   .appliedToType(tp)

tests/run/i22345c.scala

@@ -0,0 +1,4 @@
+def makeSeq[T](args: T*): Seq[T] = args
+
+@main def Test: Unit =
+  val a: Array[(Int, String)] = makeSeq[Int *: String *: EmptyTuple]().toArray