Fix KNPE due to publications processing order in Gradle 4.7

A KNPE happened because Gradle 4.7 (but not 4.8+) requested a
publication's dependencies before all other publications were created.

Issue #KT-27231 Fixed

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

@@ -132,8 +132,7 @@ class KotlinMultiplatformPlugin(
                 publishTask.onlyIf { publishTask.publication != rootPublication || project.multiplatformExtension!!.isGradleMetadataAvailable }
             }
 
-            // Create separate publications for all publishable targets
-            targets.matching { it.publishable }.all { target ->
+            fun createTargetPublication(target: KotlinTarget) {
                 val variant = target.component as KotlinVariant
                 val name = target.name
 
@@ -156,6 +155,10 @@ class KotlinMultiplatformPlugin(
                     it.execute(variantPublication)
                 }
             }
+
+            // Enforce the order of creating the publications, since the metadata publication is used in the other publications:
+            createTargetPublication(targets.getByName(METADATA_TARGET_NAME))
+            targets.matching { it.publishable && it.name != METADATA_TARGET_NAME }.all(::createTargetPublication)
         }
 
         project.components.add(kotlinSoftwareComponent)