> px 5.12.2 ./constant-folding.pl 
return, with parens       1  print HAS;
return, without parens    1  print HAS;
noreturn, with parens     1  print 1;
noreturn, without parens  1  print 1;
use, with parens          1  print 1;
use, without parens       1  print 1;