Attach expect sources to all source set tasks (KT-26977)

If kapt is enabled, there are several Kotlin compilation tasks for one source set (stub generator + compile). We should attach the expect sources to all of them.

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/kotlin/org/jetbrains/kotlin/gradle/Kapt3IT.kt

@@ -577,4 +577,14 @@ open class Kapt3IT : Kapt3BaseIT() {
 
         testResolveAllConfigurations()
     }
+
+    @Test
+    fun testMPPKaptPresence() {
+        val project = Project("mpp-kapt-presence", directoryPrefix = "kapt2")
+
+        project.build("build") {
+            assertSuccessful()
+            assertTasksExecuted(":dac:jdk:kaptGenerateStubsKotlin", ":dac:jdk:compileKotlin")
+        }
+    }
 }

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kapt2/mpp-kapt-presence/build.gradle

@@ -0,0 +1,26 @@
+buildscript {
+  ext.deps = [
+      'kotlin': [
+          'stdlib': [
+              'common': "org.jetbrains.kotlin:kotlin-stdlib-common:$kotlin_version",
+              'jdk': "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version",
+          ],
+      ],
+  ]
+
+  repositories {
+    mavenLocal()
+    mavenCentral()
+  }
+
+  dependencies {
+    classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+  }
+}
+
+allprojects {
+  repositories {
+    mavenLocal()
+    mavenCentral()
+  }
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kapt2/mpp-kapt-presence/dac/build.gradle

@@ -0,0 +1,5 @@
+apply plugin: 'org.jetbrains.kotlin.platform.common'
+
+dependencies {
+  compile deps.kotlin.stdlib.common
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kapt2/mpp-kapt-presence/dac/jdk/build.gradle

@@ -0,0 +1,10 @@
+apply plugin: 'org.jetbrains.kotlin.platform.jvm'
+apply plugin: 'kotlin-kapt'
+
+sourceCompatibility = JavaVersion.VERSION_1_8
+targetCompatibility = JavaVersion.VERSION_1_8
+
+dependencies {
+  expectedBy project(':dac')
+  implementation deps.kotlin.stdlib.jdk
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kapt2/mpp-kapt-presence/dac/jdk/src/main/kotlin/DocumentationService.kt

@@ -0,0 +1,5 @@
+package test.abc
+
+actual interface DocumentationService {
+  actual fun list(): List<Item>
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kapt2/mpp-kapt-presence/dac/src/main/kotlin/DocumentationService.kt

@@ -0,0 +1,5 @@
+package test.abc
+
+expect interface DocumentationService {
+  fun list(): List<Item>
+}

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kapt2/mpp-kapt-presence/dac/src/main/kotlin/Item.kt

@@ -0,0 +1,3 @@
+package test.abc
+
+class Item

libraries/tools/kotlin-gradle-plugin-integration-tests/src/test/resources/testProject/kapt2/mpp-kapt-presence/settings.gradle

@@ -0,0 +1,2 @@
+include ':dac'
+include ':dac:jdk'

libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinMultiplatformPlugin.kt

@@ -162,12 +162,12 @@ open class KotlinPlatformImplementationPluginBase(platformName: String) : Kotlin
     protected open fun addCommonSourceSetToPlatformSourceSet(commonSourceSet: Named, platformProject: Project) {
         platformProject.whenEvaluated {
             // At the point when the source set in the platform module is created, the task does not exist
-            val platformTask = platformProject.tasks
+            val platformTasks = platformProject.tasks
                 .withType(AbstractKotlinCompile::class.java)
-                .singleOrNull { it.sourceSetName == commonSourceSet.name } // TODO use strict check once this code is not run in K/N
+                .filter { it.sourceSetName == commonSourceSet.name } // TODO use strict check once this code is not run in K/N
 
             val commonSources = getKotlinSourceDirectorySetSafe(commonSourceSet)!!
-            if (platformTask != null) {
+            for (platformTask in platformTasks) {
                 platformTask.source(commonSources)
                 platformTask.commonSourceSet += commonSources
             }