[JS IR BE] Implement private members lowering to extract private methods from class and transform them into static function

* fix kotlin.Long
 * update tests

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/IrJsCodegenBoxTestGenerated.java

@@ -18270,6 +18270,11 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/traits/noPrivateDelegation.kt");
         }
 
+        @TestMetadata("privateInterfaceMethod.kt")
+        public void testPrivateInterfaceMethod() throws Exception {
+            runTest("compiler/testData/codegen/box/traits/privateInterfaceMethod.kt");
+        }
+
         @TestMetadata("syntheticAccessor.kt")
         public void testSyntheticAccessor() throws Exception {
             runTest("compiler/testData/codegen/box/traits/syntheticAccessor.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -19320,6 +19320,11 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/traits/noPrivateDelegation.kt");
         }
 
+        @TestMetadata("privateInterfaceMethod.kt")
+        public void testPrivateInterfaceMethod() throws Exception {
+            runTest("compiler/testData/codegen/box/traits/privateInterfaceMethod.kt");
+        }
+
         @TestMetadata("syntheticAccessor.kt")
         public void testSyntheticAccessor() throws Exception {
             runTest("compiler/testData/codegen/box/traits/syntheticAccessor.kt");

js/js.translator/testData/box/delegateProperty/clashingNameInSubclass.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // EXPECTED_REACHABLE_NODES: 1327
 fun box(): String {
     val b = B()

js/js.translator/testData/box/delegateProperty/peculiarName.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // EXPECTED_REACHABLE_NODES: 1235
 class X(private val x: String) {
     operator fun getValue(thisRef: Any?, property: Any): String = x

js/js.translator/testData/box/expression/identifierClash/privateDeclarations.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // EXPECTED_REACHABLE_NODES: 1286
 open class A {
     private val `.` = "A"

js/js.translator/testData/box/propertyOverride/overloadPrivateVal.kt

@@ -1,4 +1,3 @@
-// IGNORE_BACKEND: JS_IR
 // EXPECTED_REACHABLE_NODES: 1291
 package foo