bug#46036: fails do build on macos 10.7

[Eli Zaretskii]

> Date: Fri, 22 Jan 2021 15:57:18 +0100
> From: Riccardo Mottola <riccardo.mottola@libero.it>
> 
> Compilation of 27.1 yields:
> nsfns.m:496:33: error: unexpected type name 'BOOL': expected expression
>    NSNumber *isUbiquitousItem = @YES;
>                                  ^
> /usr/include/objc/objc.h:50:26: note: expanded from macro 'YES'
> #define YES             (BOOL)1
>                           ^
> 
> this code is guarded with MacOS 10.7, but the compiler doesn't like it.
> 
> It is as easy to write it old-style:
>    NSNumber *isUbiquitousItem = [NSNumber numberWithBool:YES];
> 
> and emacs 27.1 happily running on Lion again.

Alan, any comments on this?