[TESTS] Replace IrBackendInput if check with require

compiler/tests-common-new/tests/org/jetbrains/kotlin/test/backend/ir/JvmIrBackendFacade.kt

@@ -24,8 +24,8 @@ class JvmIrBackendFacade(
         module: TestModule,
         inputArtifact: IrBackendInput
     ): BinaryArtifacts.Jvm? {
-        if (inputArtifact !is IrBackendInput.JvmIrBackendInput) {
-            error("JvmIrBackendFacade expects IrBackendInput.JvmIrBackendInput as input")
+        require(inputArtifact is IrBackendInput.JvmIrBackendInput) {
+            "JvmIrBackendFacade expects IrBackendInput.JvmIrBackendInput as input"
         }
         val state = inputArtifact.state
         val codegenFactory = state.codegenFactory as JvmIrCodegenFactory

js/js.tests/test/org/jetbrains/kotlin/js/testNew/converters/JsKlibBackendFacade.kt

@@ -40,8 +40,8 @@ class JsKlibBackendFacade(
     }
 
     override fun transform(module: TestModule, inputArtifact: IrBackendInput): BinaryArtifacts.KLib {
-        if (inputArtifact !is IrBackendInput.JsIrBackendInput) {
-            error("JsIrBackendFacade expects IrBackendInput.JsIrBackendInput as input")
+        require(inputArtifact is IrBackendInput.JsIrBackendInput) {
+            "JsKlibBackendFacade expects IrBackendInput.JsIrBackendInput as input"
         }
 
         val configuration = testServices.compilerConfigurationProvider.getCompilerConfiguration(module)