[Bug c++/70922] -Wparentheses warning should not complain about if-else from macro expansion

[palves at redhat dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70922

--- Comment #13 from Pedro Alves <palves at redhat dot com> ---
Should have been:

   if (condition)
     ALL_OBJFILE_OSECTIONS (o, osect)
       {
          /* do something with each o / osect */
       }
   else
     return 0;

So if the ALL_OBJFILE_OSECTIONS macro contains an imbalanced if/else then the
"else" above binds to the wrong "if".  But not if the macro contains a balanced
if/else, such as in the original code.