[Native] Add comments for the Xcode 15.3 workaround

^KT-65542

native/utils/src/org/jetbrains/kotlin/konan/target/ClangArgs.kt

@@ -135,6 +135,9 @@ sealed class ClangArgs(
             add(listOf("-D__ENVIRONMENT_OS_VERSION_MIN_REQUIRED__=$environmentOsVersionMinRequired"))
         }
 
+        // Workaround to make Xcode 15.3 SDK headers work with older Clang from K/N. This should be removed after LLVM update: KT-49279
+        // We don't handle simulator targets here, because they use different machinery for macro-expansion (see DYNAMIC_TARGETS_ENABLED)
+        // YouTrack ticket:  KT-65542
         val targetConditionals = when (target) {
             KonanTarget.MACOS_ARM64, KonanTarget.MACOS_X64 -> hashMapOf(
                 "TARGET_OS_OSX" to "1",