Get rid of kotlin.Unit usage in RMI interfaces

attempt to fight mysterous "Cannot instantiate kotlin.Unit" exception.

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

@@ -22,7 +22,7 @@ import java.rmi.RemoteException
 
 interface CompilationResults : Remote {
     @Throws(RemoteException::class)
-    fun add(compilationResultCategory: Int, value: Serializable)
+    fun add(compilationResultCategory: Int, value: Serializable): Void?
 }
 
 enum class CompilationResultCategory(val code: Int) {

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

@@ -56,13 +56,13 @@ interface CompilerCallbackServicesFacade : Remote {
     fun incrementalCache_getModuleMappingData(target: TargetId): ByteArray?
 
     @Throws(RemoteException::class)
-    fun incrementalCache_registerInline(target: TargetId, fromPath: String, jvmSignature: String, toPath: String)
+    fun incrementalCache_registerInline(target: TargetId, fromPath: String, jvmSignature: String, toPath: String): Void?
 
     @Throws(RemoteException::class)
     fun incrementalCache_getClassFilePath(target: TargetId, internalClassName: String): String
 
     @Throws(RemoteException::class)
-    fun incrementalCache_close(target: TargetId)
+    fun incrementalCache_close(target: TargetId): Void?
 
     @Throws(RemoteException::class)
     fun incrementalCache_getMultifileFacadeParts(target: TargetId, internalName: String): Collection<String>?
@@ -73,7 +73,7 @@ interface CompilerCallbackServicesFacade : Remote {
     fun lookupTracker_requiresPosition(): Boolean
 
     @Throws(RemoteException::class)
-    fun lookupTracker_record(lookups: Collection<LookupInfo>)
+    fun lookupTracker_record(lookups: Collection<LookupInfo>): Void?
 
     @Throws(RemoteException::class)
     fun lookupTracker_isDoNothing(): Boolean

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

@@ -25,7 +25,7 @@ interface CompilerServicesFacadeBase : Remote {
      * Reports different kind of diagnostic messages from compile daemon to compile daemon clients (jps, gradle, ...)
      */
     @Throws(RemoteException::class)
-    fun report(category: Int, severity: Int, message: String?, attachment: Serializable?)
+    fun report(category: Int, severity: Int, message: String?, attachment: Serializable?): Void?
 }
 
 enum class ReportCategory(val code: Int) {

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

@@ -22,7 +22,7 @@ import java.rmi.RemoteException
 interface RemoteInputStream : Remote {
 
     @Throws(RemoteException::class)
-    fun close()
+    fun close(): Void?
 
     @Throws(RemoteException::class)
     fun read(length: Int): ByteArray

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

@@ -22,8 +22,8 @@ import java.rmi.RemoteException
 interface RemoteOperationsTracer : Remote {
 
     @Throws(RemoteException::class)
-    fun before(id: String)
+    fun before(id: String): Void?
 
     @Throws(RemoteException::class)
-    fun after(id: String)
+    fun after(id: String): Void?
 }

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

@@ -22,11 +22,11 @@ import java.rmi.RemoteException
 interface RemoteOutputStream : Remote {
 
     @Throws(RemoteException::class)
-    fun close()
+    fun close(): Void?
 
     @Throws(RemoteException::class)
-    fun write(data: ByteArray, offset: Int, length: Int)
+    fun write(data: ByteArray, offset: Int, length: Int): Void?
 
     @Throws(RemoteException::class)
-    fun write(dataByte: Int)
+    fun write(dataByte: Int): Void?
 }