JVM IR, FIR: set IR configuration key to true if FIR is enabled

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/compiler/KotlinToJVMBytecodeCompiler.kt

@@ -570,8 +570,6 @@ object KotlinToJVMBytecodeCompiler {
         sourceFiles: List<KtFile>,
         module: Module?
     ): GenerationState {
-        val isIR = (configuration.getBoolean(JVMConfigurationKeys.IR) ||
-                configuration.getBoolean(CommonConfigurationKeys.USE_FIR))
         val generationState = GenerationState.Builder(
             environment.project,
             ClassBuilderFactories.BINARIES,
@@ -581,13 +579,12 @@ object KotlinToJVMBytecodeCompiler {
             configuration
         )
             .codegenFactory(
-                if (isIR) JvmIrCodegenFactory(
+                if (configuration.getBoolean(JVMConfigurationKeys.IR)) JvmIrCodegenFactory(
                     configuration.get(CLIConfigurationKeys.PHASE_CONFIG) ?: PhaseConfig(jvmPhases)
                 ) else DefaultCodegenFactory
             )
             .withModule(module)
             .onIndependentPartCompilationEnd(createOutputFilesFlushingCallbackIfPossible(configuration))
-            .isIrBackend(isIR)
             .build()
 
         ProgressIndicatorAndCompilationCanceledStatus.checkCanceled()

compiler/cli/src/org/jetbrains/kotlin/cli/jvm/jvmArguments.kt

@@ -171,7 +171,7 @@ fun CompilerConfiguration.configureAdvancedJvmOptions(arguments: K2JVMCompilerAr
 
     put(JVMConfigurationKeys.PARAMETERS_METADATA, arguments.javaParameters)
 
-    put(JVMConfigurationKeys.IR, arguments.useIR && !arguments.noUseIR)
+    put(JVMConfigurationKeys.IR, (arguments.useIR && !arguments.noUseIR) || arguments.useFir)
 
     val abiStability = JvmAbiStability.fromStringOrNull(arguments.abiStability)
     if (arguments.abiStability != null) {