[K/N] XCTest launcher for CompilerOutput's TEST_BUNDLE

This change adds a Native Obj-C launcher that implements XCTestCase
and overrides defaultTestSuite property to provide XCTest with generated
test suites and test cases.

The defaultTestSuite method is essentially a starting point with runtime
initialization. It requires a `Konan_create_testSuite()` method to be
implemented in a Kotlin library that returns a list of XCTestCases.

This launcher should be compiled as a TEST_BUNDLE to be used then with
XCTest.

This commit is a part of ^KT-58928


Co-authored-by: Alexander Shabalin <Alexander.Shabalin@jetbrains.com>

Merge-request: KT-MR-12841
Merged-by: Pavel Punegov <Pavel.Punegov@jetbrains.com>

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

@@ -93,11 +93,14 @@ private fun collectLlvmModules(generationState: NativeGenerationState, generated
     val additionalBitcodeFilesToLink = generationState.llvm.additionalProducedBitcodeFiles
     val exceptionsSupportNativeLibrary = listOf(config.exceptionsSupportNativeLibrary)
             .takeIf { config.produce == CompilerOutputKind.DYNAMIC_CACHE }.orEmpty()
+    val xcTestRunnerNativeLibrary = listOf(config.xcTestLauncherNativeLibrary)
+            .takeIf { config.produce == CompilerOutputKind.TEST_BUNDLE }.orEmpty()
     val additionalBitcodeFiles = nativeLibraries +
             generatedBitcodeFiles +
             additionalBitcodeFilesToLink +
             bitcodeLibraries +
-            exceptionsSupportNativeLibrary
+            exceptionsSupportNativeLibrary +
+            xcTestRunnerNativeLibrary
 
     val runtimeNativeLibraries = config.runtimeNativeLibraries
 

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

@@ -405,6 +405,9 @@ class KonanConfig(val project: Project, val configuration: CompilerConfiguration
     internal val objCNativeLibrary: String =
             File(distribution.defaultNatives(target)).child("objc.bc").absolutePath
 
+    internal val xcTestLauncherNativeLibrary: String =
+            File(distribution.defaultNatives(target)).child("xctest_launcher.bc").absolutePath
+
     internal val exceptionsSupportNativeLibrary: String =
             File(distribution.defaultNatives(target)).child("exceptionsSupport.bc").absolutePath