[PATCH] Fix trunk bootstrap on darwin following the commit for PR16302

[Simon Martin]

Hello Manuel,

> Is it really 0?  The patch tries to not warn for constants. I will
> rather fix the warning. Could you produce a small testcase?
"gcc -E" shows that it really is "target_flags & 0".

Here's a small test case.

=== cut ===
extern int foo, bar;

#define ZERO (bar & 0)    // <- The warning shows
//#define ZERO (bar && 0) // <- It does not
//#define ZERO 0          // <- It does not

void test()
{
   if(ZERO && foo)
     return;
}
=== cut ===

Best regards,
Simon