[IR] Extract IrExternalPackageFragmentImpl.createEmptyExternalPackageFragment

plugins/android-extensions/android-extensions-compiler/src/org/jetbrains/kotlin/android/parcel/ir/AndroidSymbols.kt

@@ -444,13 +444,9 @@ class AndroidSymbols(
     }.symbol
 
     private fun createPackage(packageName: String): IrPackageFragment =
-        IrExternalPackageFragmentImpl(
-            IrExternalPackageFragmentSymbolImpl(
-                EmptyPackageFragmentDescriptor(
-                    moduleFragment.descriptor,
-                    FqName(packageName)
-                )
-            )
+        IrExternalPackageFragmentImpl.createEmptyExternalPackageFragment(
+            moduleFragment.descriptor,
+            FqName(packageName)
         )
 
     private fun createClass(

plugins/android-extensions/android-extensions-compiler/src/org/jetbrains/kotlin/android/synthetic/codegen/AndroidIrExtension.kt

@@ -60,8 +60,7 @@ private class AndroidIrTransformer(val extension: AndroidIrExtension, val plugin
 
     private fun createPackage(fqName: FqName) =
         cachedPackages.getOrPut(fqName) {
-            val descriptor = EmptyPackageFragmentDescriptor(pluginContext.moduleDescriptor, fqName)
-            IrExternalPackageFragmentImpl(IrExternalPackageFragmentSymbolImpl(descriptor))
+            IrExternalPackageFragmentImpl.createEmptyExternalPackageFragment(pluginContext.moduleDescriptor, fqName)
         }
 
     private fun createClass(fqName: FqName, isInterface: Boolean = false) =