Introduce FlexiblePhaseConfig

For dynamic Kotlin/Native driver we need a PhaseConfigurationService
that does not force us to provide a list of phases upfront.

kotlin-native/backend.native/cli.bc/src/org/jetbrains/kotlin/cli/bc/K2Native.kt

@@ -67,7 +67,11 @@ class K2Native : CLICompiler<K2NativeCompilerArguments>() {
             messageCollector.report(ERROR, "K2 does not support Native target right now")
             return ExitCode.COMPILATION_ERROR
         }
+        // TODO: Should be either of two, or PHASE_CONFIG will go away with the old driver.
+        // TODO: -Xlist-phases does not work correctly for now.
         configuration.put(CLIConfigurationKeys.PHASE_CONFIG, createPhaseConfig(toplevelPhaseErased, arguments, messageCollector))
+        configuration.put(CLIConfigurationKeys.FLEXIBLE_PHASE_CONFIG, createFlexiblePhaseConfig(arguments))
+
 
         val enoughArguments = arguments.freeArgs.isNotEmpty() || arguments.isUsefulWithoutFreeArgs
         if (!enoughArguments) {