Exclude kotlin.native internal package from modular kotlin-stdlib

Otherwise jlink fails to consume this library due to Java keyword in
package name.

#KT-29612

libraries/stdlib/jvm/build.gradle

@@ -127,7 +127,10 @@ task modularJar(type: Jar) {
     manifestAttributes(manifest, project, 'Main', true)
     classifier = 'modular'
 
-    from zipTree(jar.outputs.files.singleFile)
+    from zipTree(jar.outputs.files.singleFile).matching {
+        // Beware of Gradle problem: changing exclude spec doesn't affect Jar task up-to-dateness
+        exclude('kotlin/native/**')
+    }
     from sourceSets.java9.output
 }