kernel/x86_64: compatibility syscalls for image.cpp.

* define compat_image_info, compat_extended_image_info
to be used for respective 32-bit types of syscalls in compatibility mode.
* handle 32-bit types in _user_register_image, _user_get_image_info,
_user_get_next_image_info, other syscalls are compatible as is.

Change-Id: Ibbd33e6796208dfa70d869e36bf745bc3e18d330

headers/private/kernel/util/syscall_args.h

@@ -23,6 +23,18 @@ copy_ref_var_from_user(T *user, T &kernel)
 	return user_memcpy(&kernel, user, sizeof(T));
 }
 
+
+template<typename T>
+inline
+status_t
+copy_ref_var_from_user(T *user, T &kernel, size_t size)
+{
+	if (size != sizeof(T))
+		return B_BAD_VALUE;
+	return copy_ref_var_from_user(user, kernel);
+}
+
+
 // copy_ref_var_to_user
 template<typename T>
 inline
@@ -35,4 +47,17 @@ copy_ref_var_to_user(T &kernel, T *user)
 }
 
 
+template<typename T>
+inline
+status_t
+copy_ref_var_to_user(T &kernel, T *user, size_t size)
+{
+	if (size > sizeof(T))
+		return B_BAD_VALUE;
+	if (!IS_USER_ADDRESS(user))
+		return B_BAD_ADDRESS;
+	return user_memcpy(user, &kernel, size);
+}
+
+
 #endif	// _SYSCALL_ARGS_H