backend: do not refer phases by name

also transform KonanPhase to enum

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/KonanDriver.kt

@@ -60,15 +60,15 @@ public fun runTopLevelPhases(konanConfig: KonanConfig, environment: KotlinCoreEn
     context.irModule = module
     val phaser = PhaseManager(context)
 
-    phaser.phase("Optimizer") {
+    phaser.phase(KonanPhase.OPTIMIZER) {
         KonanLower(context).lower(module)
     }
 
-    phaser.phase("Bitcode") {
+    phaser.phase(KonanPhase.BITCODE) {
         emitLLVM(context)
     }
 
-    phaser.phase("Linker") {
+    phaser.phase(KonanPhase.LINKER) {
         //TODO: We don't have it yet.
         // invokeLinker()
     }

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/KonanLower.kt

@@ -17,20 +17,20 @@ internal class KonanLower(val context: Context) {
     fun lower(irFile: IrFile) {
         val phaser = PhaseManager(context)
 
-        phaser.phase("Lower_builtin_operators") {
+        phaser.phase(KonanPhase.LOWER_BUILTIN_OPERATORS) {
             BuiltinOperatorLowering(context).runOnFilePostfix(irFile)
         }
 
-        phaser.phase("Lower_shared_variables") {
+        phaser.phase(KonanPhase.LOWER_SHARED_VARIABLES) {
             SharedVariablesLowering(context).runOnFilePostfix(irFile)
         }
-        phaser.phase("Lower_local_functions") {
+        phaser.phase(KonanPhase.LOWER_LOCAL_FUNCTIONS) {
             LocalFunctionsLowering(context).runOnFilePostfix(irFile)
         }
-        phaser.phase("Lower_callables") {
+        phaser.phase(KonanPhase.LOWER_CALLABLES) {
             CallableReferenceLowering(context).runOnFilePostfix(irFile)
         }
-        phaser.phase("Autobox") {
+        phaser.phase(KonanPhase.AUTOBOX) {
             Autoboxing(context).lower(irFile)
         }
     }

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/KonanPhases.kt

@@ -2,26 +2,26 @@ package org.jetbrains.kotlin.backend.konan
 
 import org.jetbrains.kotlin.backend.konan.Context
 
-class KonanPhase (val description: String, 
-    var enabled: Boolean = true, var verbose: Boolean = false) {
+enum class KonanPhase(val description: String,
+                      var enabled: Boolean = true, var verbose: Boolean = false) {
+
+    BACKEND("All backend"), // TODO: it is unused
+    OPTIMIZER("IR Optimizer"),
+    LOWER_BUILTIN_OPERATORS("BuiltIn Operators Lowering"),
+    LOWER_SHARED_VARIABLES("Shared Variable Lowering"),
+    LOWER_LOCAL_FUNCTIONS("Local Function Lowering"),
+    LOWER_CALLABLES("Callable references Lowering"),
+    AUTOBOX("Autoboxing of primitive types"),
+    LOWER("IR Lowering"), // TODO: it is unused
+    BITCODE("LLVM BitCode Generation"),
+    RTTI("RTTI Generation"),
+    CODEGEN("Code Generation"),
+    METADATOR("Metadata Generation"),
+    LINKER("Link Stage");
 }
 
 object KonanPhases {
-    val phases = mapOf<String, KonanPhase> (
-        "Backend" to KonanPhase("All backend"),
-        "Optimizer" to KonanPhase("IR Optimizer"),
-        "Lower_builtin_operators" to KonanPhase("BuiltIn Operators Lowering"),
-        "Lower_shared_variables" to KonanPhase("Shared Variable Lowering"),
-        "Lower_local_functions" to KonanPhase("Local Function Lowering"),
-        "Lower_callables" to KonanPhase("Callable references Lowering"),
-        "Autobox" to KonanPhase("Autoboxing of primitive types"),
-        "Lower" to KonanPhase("IR Lowering"),
-        "Bitcode" to KonanPhase("LLVM BitCode Generation"),
-        "RTTI" to KonanPhase("RTTI Generation"),
-        "Codegen" to KonanPhase("Code Generation"),
-        "Metadator" to KonanPhase("Metadata Generation"),
-        "Linker" to KonanPhase("Link Stage")
-    )
+    val phases = KonanPhase.values().associate { it.name to it }
 
     fun config(config: KonanConfig) {
         val disabled = config.configuration.get(KonanConfigKeys.DISABLED_PHASES)
@@ -46,10 +46,8 @@ object KonanPhases {
 
 internal class PhaseManager(val context: Context)  {
 
-    internal fun phase(shortName: String, body: () -> Unit) {
+    internal fun phase(phase: KonanPhase, body: () -> Unit) {
 
-        val phase = KonanPhases.phases[shortName]
-        if (phase == null) throw Error("Unknown backend phase: $shortName")
         if (!phase .enabled) return
 
         val savePhase = context.phase

backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/IrToBitcode.kt

@@ -39,15 +39,15 @@ internal fun emitLLVM(context: Context) {
 
         val phaser = PhaseManager(context)
 
-        phaser.phase("RTTI") {
+        phaser.phase(KonanPhase.RTTI) {
             irModule.acceptVoid(RTTIGeneratorVisitor(context))
         }
 
-        phaser.phase("Codegen") {
+        phaser.phase(KonanPhase.CODEGEN) {
             irModule.acceptVoid(CodeGeneratorVisitor(context))
         }
 
-        phaser.phase("Metadator") {
+        phaser.phase(KonanPhase.METADATOR) {
             irModule.acceptVoid(MetadatorVisitor(context))
         }