fix: include correct main position and don't re-create label

src/main/wacc/backend/LabelGenerator.scala

@@ -51,9 +51,9 @@ private class LabelGenerator {
     permittedFuncFile match {
       case Some(f) if f != pos.file.getCanonicalPath => Chain.empty
       case _ =>
+        val customLabel = if name == "main" then Chain.empty else Chain(LabelDef(name))
         permittedFuncFile = Some(pos.file.getCanonicalPath)
-        Chain(
-          LabelDef(name),
+        customLabel ++ Chain(
           Directive.Location(getDebugFile(pos.file), pos.line, None),
           Directive.Type(label, SymbolType.Function),
           Directive.Func(name, label)