[JS IR] Fix IrGetClass for Throwable successors

- add test

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/ClassReferenceLowering.kt

@@ -42,7 +42,6 @@ class ClassReferenceLowering(val context: JsIrBackendContext) : FileLoweringPass
             IrType::isDouble to "doubleClass",
             IrType::isArray to "arrayClass",
             IrType::isString to "stringClass",
-            IrType::isThrowable to "throwableClass",
             IrType::isBooleanArray to "booleanArrayClass",
             IrType::isCharArray to "charArrayClass",
             IrType::isByteArray to "byteArrayClass",
@@ -60,6 +59,7 @@ class ClassReferenceLowering(val context: JsIrBackendContext) : FileLoweringPass
         mapOf(
             IrType::isAny to "anyClass",
             IrType::isNumber to "numberClass",
+            IrType::isThrowable to "throwableClass",
             IrType::isNothing to "nothingClass"
         ).mapValues {
             primitiveClassProperty(it.value)

js/js.tests/test/org/jetbrains/kotlin/js/test/ir/semantics/IrBoxJsTestGenerated.java

@@ -6698,6 +6698,11 @@ public class IrBoxJsTestGenerated extends AbstractIrBoxJsTest {
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("js/js.translator/testData/box/reflection"), Pattern.compile("^([^_](.+))\\.kt$"), TargetBackend.JS_IR, true);
         }
 
+        @TestMetadata("classJsName.kt")
+        public void testClassJsName() throws Exception {
+            runTest("js/js.translator/testData/box/reflection/classJsName.kt");
+        }
+
         @TestMetadata("external.kt")
         public void testExternal() throws Exception {
             runTest("js/js.translator/testData/box/reflection/external.kt");

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

@@ -6728,6 +6728,11 @@ public class BoxJsTestGenerated extends AbstractBoxJsTest {
             KotlinTestUtils.assertAllTestsPresentByMetadata(this.getClass(), new File("js/js.translator/testData/box/reflection"), Pattern.compile("^([^_](.+))\\.kt$"), TargetBackend.JS, true);
         }
 
+        @TestMetadata("classJsName.kt")
+        public void testClassJsName() throws Exception {
+            runTest("js/js.translator/testData/box/reflection/classJsName.kt");
+        }
+
         @TestMetadata("external.kt")
         public void testExternal() throws Exception {
             runTest("js/js.translator/testData/box/reflection/external.kt");

js/js.translator/testData/box/reflection/classJsName.kt

@@ -0,0 +1,13 @@
+// EXPECTED_REACHABLE_NODES: 1282
+
+
+fun Throwable.className() = this::class.simpleName!!
+
+class O : Error()
+class K : Error()
+
+fun box(): String {
+    val o = O()
+    val k = K()
+    return o.className() + k.className()
+}