Build java9 modular artifacts under 'modular' classifier

Provide additional modular artifacts as a workaround for KT-21266

Update module-info declarations:
  - add new packages
  - add exports and opens for internal PlatformImplementations
  - remove exports of kotlin.coroutines.experimental.*

#KT-27919 Fixed

libraries/reflect/api/build.gradle

@@ -44,8 +44,7 @@ jar {
 
 task java9Jar(type: Jar) {
     classifier = "java9"
-    // TODO: enable as soon as this doesn't cause D8/DX to crash
-    // from sourceSets.java9.output
+    from sourceSets.java9.output
 }
 
 artifacts {

libraries/reflect/build.gradle.kts

@@ -109,7 +109,7 @@ class KotlinModuleShadowTransformer(private val logger: Logger) : Transformer {
 val reflectShadowJar by task<ShadowJar> {
     classifier = "shadow"
     version = null
-    callGroovy("manifestAttributes", manifest, project, "Main", true)
+    callGroovy("manifestAttributes", manifest, project, "Main" /*true*/)
 
     from(project(":core:descriptors.jvm").mainSourceSet.resources) {
         include("META-INF/services/**")
@@ -191,6 +191,16 @@ val sourcesJar = sourcesJar(sourceSet = null) {
 val result by task<Jar> {
     dependsOn(proguard)
     from(zipTree(file(proguardOutput)))
+//    from(zipTree(reflectShadowJar.archivePath)) {
+//        include("META-INF/versions/**")
+//    }
+    callGroovy("manifestAttributes", manifest, project, "Main" /*true*/)
+}
+
+val modularJar by task<Jar> {
+    dependsOn(proguard)
+    classifier = "modular"
+    from(zipTree(file(proguardOutput)))
     from(zipTree(reflectShadowJar.archivePath)) {
         include("META-INF/versions/**")
     }
@@ -208,12 +218,13 @@ artifacts {
     val artifactJar = mapOf(
         "file" to result.outputs.files.single(),
         "builtBy" to result,
-        "name" to property("archivesBaseName")
+        "name" to base.archivesBaseName
     )
 
     add(mainJar.name, artifactJar)
     add("runtime", artifactJar)
     add("archives", artifactJar)
+    add("archives", modularJar)
 }
 
 javadocJar()