Add AnalysisHandlerExtension extension point for K2Native

frontendPhase is moved out of back phases to allow frontend only mode.

AnalysisHandlerExtension allows compiler plugins to:
1. Intercept and override the default analysis.
2. Utilize the compiler infrastructure to do custom analysis.

A well know plugin on the JVM platform is KAPT.

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

@@ -180,6 +180,7 @@ class K2Native : CLICompiler<K2NativeCompilerArguments>() {
                 put(PRINT_DESCRIPTORS, arguments.printDescriptors)
                 put(PRINT_LOCATIONS, arguments.printLocations)
                 put(PRINT_BITCODE, arguments.printBitCode)
+                put(PRINT_FILES, arguments.printFiles)
 
                 put(PURGE_USER_LIBS, arguments.purgeUserLibs)
 

kotlin-native/backend.native/cli.bc/src/org/jetbrains/kotlin/cli/bc/K2NativeCompilerArguments.kt

@@ -199,6 +199,9 @@ class K2NativeCompilerArguments : CommonCompilerArguments() {
     @Argument(value = "-Xprint-locations", deprecatedName = "--print_locations", description = "Print locations")
     var printLocations: Boolean = false
 
+    @Argument(value = "-Xprint-files", description = "Print files")
+    var printFiles: Boolean = false
+
     @Argument(value="-Xpurge-user-libs", deprecatedName = "--purge_user_libs", description = "Don't link unused libraries even explicitly specified")
     var purgeUserLibs: Boolean = false