[IR] Extract IrExternalPackageFragmentImpl.createEmptyExternalPackageFragment

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmSymbols.kt

@@ -87,7 +87,7 @@ class JvmSymbols(
 
 
     private fun createPackage(fqName: FqName): IrPackageFragment =
-        IrExternalPackageFragmentImpl(IrExternalPackageFragmentSymbolImpl(EmptyPackageFragmentDescriptor(context.state.module, fqName)))
+        IrExternalPackageFragmentImpl.createEmptyExternalPackageFragment(context.state.module, fqName)
 
     private fun createClass(
         fqName: FqName,

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/descriptors/SharedVariablesManager.kt

@@ -32,10 +32,8 @@ class JvmSharedVariablesManager(
     val symbols: JvmSymbols,
     val irBuiltIns: IrBuiltIns
 ) : SharedVariablesManager {
-    private val jvmInternalPackage = IrExternalPackageFragmentImpl(
-        IrExternalPackageFragmentSymbolImpl(
-            EmptyPackageFragmentDescriptor(module, FqName("kotlin.jvm.internal"))
-        )
+    private val jvmInternalPackage = IrExternalPackageFragmentImpl.createEmptyExternalPackageFragment(
+        module, FqName("kotlin.jvm.internal")
     )
 
     private val refNamespaceClass = jvmInternalPackage.addClass {

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/AdditionalClassAnnotationLowering.kt

@@ -14,7 +14,6 @@ import org.jetbrains.kotlin.config.JvmTarget
 import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.annotations.KotlinRetention
 import org.jetbrains.kotlin.descriptors.annotations.KotlinTarget
-import org.jetbrains.kotlin.descriptors.impl.EmptyPackageFragmentDescriptor
 import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
 import org.jetbrains.kotlin.ir.builders.declarations.addValueParameter
 import org.jetbrains.kotlin.ir.builders.declarations.buildClass
@@ -54,13 +53,9 @@ private class AdditionalClassAnnotationLowering(private val context: JvmBackendC
 
     // TODO: import IR structures from the library?
 
-    private val annotationPackage: IrPackageFragment = IrExternalPackageFragmentImpl(
-        IrExternalPackageFragmentSymbolImpl(
-            EmptyPackageFragmentDescriptor(
-                context.ir.irModule.descriptor,
-                FqName("java.lang.annotation")
-            )
-        )
+    private val annotationPackage: IrPackageFragment = IrExternalPackageFragmentImpl.createEmptyExternalPackageFragment(
+        context.ir.irModule.descriptor,
+        FqName("java.lang.annotation")
     )
 
     private fun buildAnnotationClass(