Add kotlinx-html test

Among other things it tests the packagePartProvider fix above

libraries/tools/kotlin-main-kts-test/testData/kotlinx-html.main.kts

@@ -0,0 +1,15 @@
+#!/usr/bin/env kotlinc -cp dist/kotlinc/lib/kotlin-main-kts.jar -script
+
+@file:Repository("https://jcenter.bintray.com")
+@file:DependsOn("org.jetbrains.kotlinx:kotlinx-html-jvm:0.6.11")
+
+import kotlinx.html.*; import kotlinx.html.stream.*; import kotlinx.html.attributes.*
+
+BooleanEncoder()
+
+print(createHTML().html {
+    body {
+        h1 { +"Hello, World!" }
+    }
+})
+