Scala 2.13.9 with -Wnonunit-statement and xml literals result in false positives

[SimY4]

Reproduction steps

Scala version: 2.13.9

class C {
  val xml = <xml><elem></elem></xml>
  
  def some = xml
}

Problem

Warning produced on line 2:
unused value of type scala.xml.NodeBuffer (add : Unit to discard silently)

Expected: the code compiles without warning.

[SethTisue]

good catch, thanks! @som-snytt will likely want to take a look

[som-snytt]

Thanks, I'll take a look. My umbrella ticket is #12653, but I'll follow up here.

I would not have thought to check XML -- in case there is another ticket for "things we never compile when we compile the compiler."

[SethTisue]

@som-snytt I'm putting this on Backlog, but feel free to try to fix it for 2.13.11 anyway, if you're so inclined :-)

[som-snytt]

This is due to a signature in the XML library implementation, so I have PR'd there.

I'll PR a test here, but that will only test a "dummy" API.