fixed bug #1661 Compiling --pstack fails with binutils 2.13.90
fixed bug #1661 Compiling --pstack fails with binutils 2.13.90

fixed wrong execution of bfd_get_symtab_upper_bound in pstack/pstack.c
for files which don't contain symbols..
to avoid failing of new binutils (old binutils returned 0 in this case)


pstack/pstack.c:
  fixed bug #1661 Compiling --pstack fails with binutils 2.13.90
  
  fixed wrong execution of bfd_get_symtab_upper_bound 
  for files which don't contain symbols..
  to avoid failing of new binutils (old binutils returned 0 in this case)

natsys/mariadb_10.2,flynn1973/mariadb-aix,ollie314/server,natsys/mariadb_10.2,flynn1973/mariadb-aix,flynn1973/mariadb-aix,natsys/mariadb_10.2,flynn1973/mariadb-aix,flynn1973/mariadb-aix,davidl-zend/zenddbi,davidl-zend/zenddbi,davidl-zend/zenddbi,davidl-zend/zenddbi,flynn1973/mariadb-aix,slanterns/server,ollie314/server,ollie314/server,davidl-zend/zenddbi,ollie314/server,ollie314/server,flynn1973/mariadb-aix,davidl-zend/zenddbi,flynn1973/mariadb-aix,natsys/mariadb_10.2,davidl-zend/zenddbi,ollie314/server,natsys/mariadb_10.2,natsys/mariadb_10.2,natsys/mariadb_10.2,davidl-zend/zenddbi,davidl-zend/zenddbi,davidl-zend/zenddbi,ollie314/server,ollie314/server,natsys/mariadb_10.2,flynn1973/mariadb-aix,davidl-zend/zenddbi,natsys/mariadb_10.2,ollie314/server,flynn1973/mariadb-aix,ollie314/server,natsys/mariadb_10.2,flynn1973/mariadb-aix,ollie314/server,natsys/mariadb_10.2