[K/N] Refactor unhandled exception handling API

* Do not reset unhandled exception hook
* Add processUnhandledException to perform default unhandled exception
  processing
* Add terminateWithUnhandledException to report the unhandled exception
  and terminate the program
* Use the default unhandled exception processing in entrypoint, interop
  boundaries and in Worker.executeAfter
* Add -Xworker-exception-handling to control exception processing of
  Worker.executeAfter. By default its the old behaviour with the old MM,
  and new behaviour with the new MM.

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

@@ -329,6 +329,15 @@ class K2Native : CLICompiler<K2NativeCompilerArguments>() {
                     }
                 })
                 put(PROPERTY_LAZY_INITIALIZATION, arguments.propertyLazyInitialization)
+                put(WORKER_EXCEPTION_HANDLING, when (arguments.workerExceptionHandling) {
+                    null -> if (memoryModel == MemoryModel.EXPERIMENTAL) WorkerExceptionHandling.USE_HOOK else WorkerExceptionHandling.LEGACY
+                    "legacy" -> WorkerExceptionHandling.LEGACY
+                    "use-hook" -> WorkerExceptionHandling.USE_HOOK
+                    else -> {
+                        configuration.report(ERROR, "Unsupported worker exception handling mode ${arguments.workerExceptionHandling}")
+                        WorkerExceptionHandling.LEGACY
+                    }
+                })
             }
         }
     }

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

@@ -320,6 +320,14 @@ class K2NativeCompilerArguments : CommonCompilerArguments() {
     @Argument(value="-Xruntime-asserts-mode", valueDescription = "<mode>", description = "Enable asserts in runtime. Possible values: 'ignore', 'log', 'panic'")
     var runtimeAssertsMode: String? = "ignore"
 
+    // TODO: Remove when legacy MM is gone.
+    @Argument(
+            value = "-Xworker-exception-handling",
+            valueDescription = "<mode>",
+            description = "Unhandled exception processing in Worker.executeAfter. Possible values: 'legacy', 'use-hook'. The default value is 'legacy', for -memory-model experimental the default value is 'use-hook'"
+    )
+    var workerExceptionHandling: String? = null
+
     override fun configureAnalysisFlags(collector: MessageCollector, languageVersion: LanguageVersion): MutableMap<AnalysisFlag<*>, Any> =
             super.configureAnalysisFlags(collector, languageVersion).also {
                 val useExperimental = it[AnalysisFlags.useExperimental] as List<*>