Use parallel-collections in 2.13 scala native

Was previously impossible, as parallel-collections
library was not yet released for scala native as of making
the scala native PR.

build.sbt

@@ -116,7 +116,7 @@ lazy val sysops = crossProject(JVMPlatform, NativePlatform)
         case Some((2, 12)) =>
           Seq("com.github.bigwheel" %% "util-backports" % "2.1")
         case Some((2, 13)) =>
-          Seq("org.scala-lang.modules" %% "scala-parallel-collections" % "1.2.0")
+          Seq("org.scala-lang.modules" %%% "scala-parallel-collections" % "1.2.0")
         case _ => Seq()
       }
     },

scalafmt-sysops/shared/src/main/scala-2.12/org/scalafmt/CompatCollections.scala

@@ -0,0 +1,6 @@
+package org.scalafmt
+
+private[scalafmt] object CompatCollections {
+  val JavaConverters = scala.collection.JavaConverters
+  object ParConverters
+}

scalafmt-sysops/shared/src/main/scala-2.13/org/scalafmt/CompatCollections.scala

@@ -0,0 +1,6 @@
+package org.scalafmt
+
+private[scalafmt] object CompatCollections {
+  val JavaConverters = scala.jdk.CollectionConverters
+  val ParConverters = scala.collection.parallel.CollectionConverters
+}

scalafmt-tests/jvm/src/test/scala/org/scalafmt/ScalafmtProps.scala

@@ -23,7 +23,7 @@ class ScalafmtProps extends FunSuite with FormatAssertions {
     val corpus = Corpus.files(
       // TODO(olafur) remove once testkit 1.7 is out
       Corpus.fastparse.copy(Corpus.fastparse.url.replace("olafurpg", "scalameta")),
-    ).take(count).toBuffer.compatPar
+    ).take(count).toBuffer.par
     SyntaxAnalysis.run[Observation[Bug]](corpus) { file =>
       val code = file.read
       try Scalafmt.format(code, config) match {