address more comments

kernel-laws/jvm/src/test/scala/cats/kernel/laws/JvmLawTests.scala

@@ -25,6 +25,7 @@ package laws
 import cats.kernel.compat.scalaVersionSpecific.*
 import cats.kernel.instances.currency.*
 import cats.kernel.laws.discipline.*
+import cats.kernel.laws.scalaVersionSpecific.*
 import munit.DisciplineSuite
 import java.util.Currency
 import org.scalacheck.{Arbitrary, Cogen, Gen}

kernel-laws/shared/src/test/scala-2.12/cats/kernel/laws/scalaVersionSpecific.scala

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2015 Typelevel
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+package cats.kernel.laws
+import scala.annotation.{Annotation, StaticAnnotation}
+import scala.collection.{mutable, IterableLike, TraversableLike}
+import scala.collection.JavaConverters._
+
+private[cats] object scalaVersionSpecific {
+
+  implicit class iterableExtension[A](private val s: java.lang.Iterable[A]) extends AnyVal {
+    def asScala: Iterable[A] = iterableAsScalaIterable(s)
+  }
+}

kernel/src/main/scala-2.12/cats/kernel/compat/scalaVersionSpecific.scala

@@ -21,8 +21,7 @@
 
 package cats.kernel.compat
 import scala.annotation.{Annotation, StaticAnnotation}
-import scala.collection.{mutable, IterableLike, TraversableLike}
-import scala.collection.convert.ImplicitConversionsToScala.*
+import scala.collection.{IterableLike, TraversableLike}
 
 private[cats] object scalaVersionSpecific {
 
@@ -51,8 +50,4 @@ private[cats] object scalaVersionSpecific {
       that: T
     )(implicit w1: A => TraversableLike[El1, Repr1], w2: T => IterableLike[El2, Repr2]) = (a, that).zipped
   }
-
-  implicit class setExtension[A](private val s: java.util.Set[A]) extends AnyVal {
-    def asScala: mutable.Set[A] = `set asScala`(s)
-  }
 }

kernel/src/main/scala-2.13+/cats/kernel/compat/scalaVersionSpecific.scala

@@ -24,8 +24,7 @@ package kernel
 
 package compat
 import scala.annotation.{Annotation, StaticAnnotation}
-import scala.collection.mutable
-import scala.jdk.CollectionConverters.*
+import scala.jdk.javaapi.CollectionConverters
 
 private[cats] object scalaVersionSpecific {
 
@@ -39,6 +38,6 @@ private[cats] object scalaVersionSpecific {
   }
 
   implicit class setExtension[A](private val s: java.util.Set[A]) extends AnyVal {
-    def asScala: mutable.Set[A] = SetHasAsScala(s).asScala
+    def asScala: Iterable[A] = CollectionConverters.asScala(x)
   }
 }