[ObjCExport] Add inner classes translation

KT-66339

native/objcexport-header-generator/testData/headers/innerClass/!innerClass.h

@@ -0,0 +1,37 @@
+#import <Foundation/NSArray.h>
+#import <Foundation/NSDictionary.h>
+#import <Foundation/NSError.h>
+#import <Foundation/NSObject.h>
+#import <Foundation/NSSet.h>
+#import <Foundation/NSString.h>
+#import <Foundation/NSValue.h>
+
+@class Foo;
+
+NS_ASSUME_NONNULL_BEGIN
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunknown-warning-option"
+#pragma clang diagnostic ignored "-Wincompatible-property-type"
+#pragma clang diagnostic ignored "-Wnullability"
+
+#pragma push_macro("_Nullable_result")
+#if !__has_feature(nullability_nullable_result)
+#undef _Nullable_result
+#define _Nullable_result _Nullable
+#endif
+
+__attribute__((objc_subclassing_restricted))
+@interface Foo : Base
+- (instancetype)init __attribute__((swift_name("init()"))) __attribute__((objc_designated_initializer));
++ (instancetype)new __attribute__((availability(swift, unavailable, message="use object initializers instead")));
+@end
+
+__attribute__((objc_subclassing_restricted))
+__attribute__((swift_name("Foo.Inner")))
+@interface FooInner : Base
+- (instancetype)initWith:(Foo *)receiver __attribute__((swift_name("init(_:)"))) __attribute__((objc_designated_initializer));
+@end
+
+#pragma pop_macro("_Nullable_result")
+#pragma clang diagnostic pop
+NS_ASSUME_NONNULL_END