[K/N] Properly support watchosArm64

kotlin-native/Interop/StubGenerator/src/main/kotlin/org/jetbrains/kotlin/native/interop/gen/AbiSpecific.kt

@@ -18,12 +18,7 @@ import org.jetbrains.kotlin.native.interop.indexer.*
 internal fun Type.isStret(target: KonanTarget): Boolean {
     val unwrappedType = this.unwrapTypedefs()
     val abiInfo: ObjCAbiInfo = when (target.architecture) {
-        Architecture.ARM64 -> {
-            // Currently, cinterop works with watchos_arm64 as with watchos_arm32.
-            // TODO: ABI for watchos_arm64 should be revisited after LLVM update.
-            require(target != KonanTarget.WATCHOS_ARM64)
-            DarwinArm64AbiInfo()
-        }
+        Architecture.ARM64 -> DarwinArm64AbiInfo()
 
         Architecture.X64 -> DarwinX64AbiInfo()
 
@@ -88,6 +83,9 @@ class DarwinArm32AbiInfo(private val target: KonanTarget) : ObjCAbiInfo {
     }
 }
 
+/**
+ * Remember about arm64_32!
+ */
 class DarwinArm64AbiInfo : ObjCAbiInfo {
     override fun shouldUseStret(returnType: Type): Boolean {
         // On aarch64 stret is never the case, since an implicit argument gets passed on x8.

kotlin-native/Interop/StubGenerator/src/main/kotlin/org/jetbrains/kotlin/native/interop/gen/jvm/main.kt

@@ -288,13 +288,7 @@ private fun processCLib(flavor: KotlinPlatform, cinteropArguments: CInteropArgum
 
     val (nativeIndex, compilation) = plugin.buildNativeIndex(library, verbose)
 
-    // Our current approach to arm64_32 support is to compile armv7k version of bitcode
-    // for arm64_32. That's the reason for this substitution.
-    // TODO: Add proper support with the next LLVM update.
-    val target = when (tool.target) {
-        KonanTarget.WATCHOS_ARM64 -> KonanTarget.WATCHOS_ARM32
-        else -> tool.target
-    }
+    val target = tool.target
 
     val klibSuffix = CompilerOutputKind.LIBRARY.suffix(target)
     val moduleName = cinteropArguments.moduleName

kotlin-native/konan/konan.properties

@@ -393,8 +393,7 @@ targetToolchain.macos_arm64-watchos_arm64 = target-toolchain-xcode_13_1
 
 targetTriple.watchos_arm64 = arm64_32-apple-watchos
 targetSysRoot.watchos_arm64 = target-sysroot-xcode_13_1-watchos
-# TODO: Use -target-cpu=apple-s4 when we start generating bitcode for arm64_32.
-targetCpu.watchos_arm64 = cortex-a7
+targetCpu.watchos_arm64 = apple-s4
 clangFlags.watchos_arm64 = -cc1 -emit-obj -disable-llvm-passes -x ir -mllvm -aarch64-watch-bitcode-compatibility \
   -mllvm -arm-bitcode-compatibility
 clangNooptFlags.watchos_arm64 = -O1