dont introduce new API

Author: bishabosha

compiler/src/dotty/tools/backend/jvm/BCodeSkelBuilder.scala

@@ -626,7 +626,7 @@ trait BCodeSkelBuilder extends BCodeHelpers {
         val nr =
           val sourcePos = tree.sourcePos
           (
-            if sourcePos.exists then sourcePos.finalPosition.line
+            if sourcePos.exists then sourcePos.source.positionInUltimateSource(sourcePos).line
             else ctx.source.offsetToLine(tree.span.point) // fallback
           ) + 1
 

compiler/src/dotty/tools/dotc/util/SourcePosition.scala

@@ -79,11 +79,6 @@ extends SrcPos, interfaces.SourcePosition, Showable {
     rec(this)
   }
 
-  def finalPosition: SourcePosition = {
-    source.positionInUltimateSource(this)
-  }
-
-
   override def toString: String =
     s"${if (source.exists) source.file.toString else "(no source)"}:$span"