Check for batch PSI children update when invalidating package cache

 #KT-17868 fixed

Author: semoro

idea/idea-analysis/src/org/jetbrains/kotlin/idea/caches/PerModulePackageCacheService.kt

@@ -36,6 +36,7 @@ import org.jetbrains.kotlin.idea.stubindex.PackageIndexUtil
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.psi.KtPackageDirective
+import org.jetbrains.kotlin.psi.psiUtil.getChildrenOfType
 import org.jetbrains.kotlin.psi.psiUtil.getParentOfType
 import java.util.concurrent.ConcurrentMap
 
@@ -73,6 +74,11 @@ class KotlinPackageStatementPsiTreeChangePreprocessor(private val project: Proje
                 if (child.getParentOfType<KtPackageDirective>(false) != null)
                     project.service<PerModulePackageCacheService>().notifyPackageChange(file)
             }
+            PsiTreeChangeEventImpl.PsiEventType.CHILDREN_CHANGED -> {
+                val parent = event.parent ?: return
+                if (parent.getChildrenOfType<KtPackageDirective>().any())
+                    project.service<PerModulePackageCacheService>().notifyPackageChange(file)
+            }
             else -> {
             }
         }