[K/N] Convert :kotlin-native:Interop:StubGenerator

Use folder structure from the rest of the project and build it by
the bootstrap compiler.

kotlin-native/Interop/StubGenerator/testResources/ForwardDeclarations/objcWithDefinition/included.h

@@ -0,0 +1,8 @@
+@class Class3;
+@protocol Protocol3;
+
+@interface Class4
+@end
+
+@protocol Protocol4
+@end

kotlin-native/Interop/StubGenerator/testResources/ForwardDeclarations/objcWithDefinition/main.def

@@ -0,0 +1,2 @@
+headers = main.h
+language = Objective-C

kotlin-native/Interop/StubGenerator/testResources/ForwardDeclarations/objcWithDefinition/main.h

@@ -0,0 +1,31 @@
+#import "included.h"
+
+@class Class1, Class2;
+@class Class2;
+
+@interface Class1
+@end
+
+@interface Class2
+@end
+
+@class Class2;
+
+@protocol Protocol1;
+
+@protocol Protocol1
+@end
+
+@protocol Protocol2;
+
+@protocol Protocol2
+@end
+
+@interface Class3
+@end
+
+@protocol Protocol3
+@end
+
+@class Class4;
+@protocol Protocol4;