[stdlib-mpp] Switch kotlin-stdlib project to multiplatform

#KT-56106

libraries/stdlib/build.gradle.kts

@@ -980,4 +980,13 @@ private class ComponentWithExternalVariants(
     override fun getVariants(): Set<SoftwareComponent> = externalComponents
 }
 
-// endregion
+// endregion
+
+// for legacy intra-project dependencies
+for (name in listOf("sources", "distSources")) {
+    val sourcesConfiguration = configurations.getOrCreate(name).apply {
+        isCanBeResolved = false
+        isCanBeConsumed = true
+    }
+    artifacts.add(sourcesConfiguration.name, tasks["jvmSourcesJar"])
+}