Compile multiplatform projects with daemon

compiler/daemon/daemon-common/src/org/jetbrains/kotlin/daemon/common/CompileService.kt

@@ -31,7 +31,8 @@ interface CompileService : Remote {
 
     enum class TargetPlatform : Serializable {
         JVM,
-        JS
+        JS,
+        METADATA
     }
 
     companion object {

compiler/daemon/src/org/jetbrains/kotlin/daemon/KotlinCompileDaemon.kt

@@ -19,6 +19,7 @@ package org.jetbrains.kotlin.daemon
 import org.jetbrains.kotlin.cli.common.CLICompiler
 import org.jetbrains.kotlin.cli.js.K2JSCompiler
 import org.jetbrains.kotlin.cli.jvm.K2JVMCompiler
+import org.jetbrains.kotlin.cli.metadata.K2MetadataCompiler
 import org.jetbrains.kotlin.daemon.common.*
 import java.io.File
 import java.io.IOException
@@ -125,9 +126,11 @@ object KotlinCompileDaemon {
             val compilerSelector = object : CompilerSelector {
                 private val jvm by lazy { K2JVMCompiler() }
                 private val js by lazy { K2JSCompiler() }
+                private val metadata by lazy { K2MetadataCompiler() }
                 override fun get(targetPlatform: CompileService.TargetPlatform): CLICompiler<*> = when (targetPlatform) {
                     CompileService.TargetPlatform.JVM -> jvm
                     CompileService.TargetPlatform.JS -> js
+                    CompileService.TargetPlatform.METADATA -> metadata
                 }
             }
             // timer with a daemon thread, meaning it should not prevent JVM to exit normally