Unit test failures on 2.13.12

[som-snytt]

Unit tests fail on the Scala 2 community build.

Configuration (required)

HEAD

Problem

[scalafmt] [error] Failed tests:
[scalafmt] [error] 	org.scalafmt.FidelityTest
[scalafmt] [error] 	org.scalafmt.FormatTests

Notes

It looks like Tokens#last doesn't throw on empty Tokens. Scalafmt should handle empty tokens:

defnBeforeTemplate(leftOwner).filter(_.tokens.nonEmpty).map { x =>
  val policyEnd = Policy.End.On(x.tokens.last)
  delayedBreakPolicy(policyEnd)(forceNewlineBeforeExtends)
}

(I didn't pursue a fix.)

Noticed at scala/community-build#1680 (comment)

==> X org.scalafmt.FormatTests.unit/Annotations.stat:59: #1640                                       |  0.001s org.scalafmt.util.FormatException: java.util.NoSuchElementException: last of empty IndexedSeq
    at org.scalafmt.FormatTests.run(FormatTests.scala:56)
    at org.scalafmt.FormatTests.$anonfun$new$3(FormatTests.scala:33)
    at org.scalafmt.FormatTests.$anonfun$new$3$adapted(FormatTests.scala:33)
    at org.scalafmt.util.CanRunTests.$anonfun$runTest$2(CanRunTests.scala:19)
Caused by: java.util.NoSuchElementException: last of empty IndexedSeq
    at scala.collection.IndexedSeqOps.last(IndexedSeq.scala:110)
    at scala.collection.IndexedSeqOps.last$(IndexedSeq.scala:105)
    at scala.meta.tokens.Tokens.last(Tokens.scala:29)
    at org.scalafmt.internal.Router.$anonfun$getSplitsImpl$118(Router.scala:838)
    at scala.Option.map(Option.scala:242)
    at org.scalafmt.internal.Router.getSplitsImpl(Router.scala:837)