[K/N] Add objcClassesIncludingCategories cinterop property

It allows to list Objective-C classes that should include
corresponding categories from the same file.
The current implementation is super-simple and slow, but
it is OK since it is not intended to be a general-purpose
solution for now.

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

@@ -568,6 +568,7 @@ internal fun buildNativeLibrary(
 
     val headerExclusionPolicy = HeaderExclusionPolicyImpl(imports)
 
+    val objCClassesIncludingCategories = def.config.objcClassesIncludingCategories.toSet()
     return NativeLibrary(
             includes = includes,
             additionalPreambleLines = compilation.additionalPreambleLines,
@@ -576,7 +577,8 @@ internal fun buildNativeLibrary(
             language = compilation.language,
             excludeSystemLibs = excludeSystemLibs,
             headerExclusionPolicy = headerExclusionPolicy,
-            headerFilter = headerFilter
+            headerFilter = headerFilter,
+            objCClassesIncludingCategories = objCClassesIncludingCategories
     )
 }