Add lambda configurable languageSettings function in KotlinSourceSet

Function with Groovy Closure is already exists, it provides DSL parity
#KT-44834 Fixed

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

@@ -16,6 +16,7 @@ interface KotlinSourceSet : Named, HasKotlinDependencies {
     val resources: SourceDirectorySet
 
     val languageSettings: LanguageSettingsBuilder
+    fun languageSettings(configure: LanguageSettingsBuilder.() -> Unit): LanguageSettingsBuilder
     fun languageSettings(configureClosure: Closure<Any?>): LanguageSettingsBuilder
 
     fun dependsOn(other: KotlinSourceSet)

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

@@ -692,6 +692,28 @@ class NewMultiplatformIT : BaseGradleIT() {
         }
     }
 
+    @Test
+    fun testLanguageSettingsClosureForKotlinDsl() = with(transformNativeTestProjectWithPluginDsl("sample-lib-gradle-kotlin-dsl", gradleVersion, "new-mpp-lib-and-app")) {
+        gradleBuildScript().appendText(
+                "\n" + """
+            kotlin.sourceSets.all {
+                languageSettings {
+                    languageVersion = "1.3"
+                    apiVersion = "1.3" 
+                }
+            }
+        """.trimIndent()
+        )
+
+        listOf("compileKotlinMetadata", "compileKotlinJvm6", "compileKotlinNodeJs").forEach {
+            build(it) {
+                assertSuccessful()
+                assertTasksExecuted(":$it")
+                assertContains("-language-version 1.3", "-api-version 1.3")
+            }
+        }
+    }
+
     @Test
     fun testLanguageSettingsApplied() = with(transformNativeTestProject("sample-lib", gradleVersion, "new-mpp-lib-and-app")) {
         gradleBuildScript().appendText(

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

@@ -71,6 +71,9 @@ class DefaultKotlinSourceSet(
         ConfigureUtil.configure(configureClosure, this)
     }
 
+    override fun languageSettings(configure: LanguageSettingsBuilder.() -> Unit): LanguageSettingsBuilder =
+            languageSettings.apply { configure(this) }
+
     override fun getName(): String = displayName
 
     override fun dependencies(configure: KotlinDependencyHandler.() -> Unit): Unit =

libraries/tools/kotlin-gradle-plugin/src/test/kotlin/org/jetbrains/kotlin/gradle/plugin/sources/SourceSetVisibilityInferenceTest.kt

@@ -253,6 +253,7 @@ class MockKotlinSourceSet(private val name: String) : KotlinSourceSet {
     override val resources: SourceDirectorySet get() = throw UnsupportedOperationException()
     override val languageSettings: LanguageSettingsBuilder get() = throw UnsupportedOperationException()
     override fun languageSettings(configureClosure: Closure<Any?>): LanguageSettingsBuilder = languageSettings
+    override fun languageSettings(configure: LanguageSettingsBuilder.() -> Unit): LanguageSettingsBuilder = languageSettings
     override val apiMetadataConfigurationName: String get() = throw UnsupportedOperationException()
     override val implementationMetadataConfigurationName: String get() = throw UnsupportedOperationException()
     override val compileOnlyMetadataConfigurationName: String get() = throw UnsupportedOperationException()