Merge r1534860 from trunk:

 * r1534860
   Remove -fwhole_program flag from optimized GCC builds.
   Justification:
     As described in http://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html,
     -flto is superior and should not be combined with -fwhole-program.
     As it turns out, -fwhole_program causes issues with llvm and other
     sources indicated that the flag might not be particularly useful to
     begin with.
   Votes:
     +1: stefan2, breser, brane


git-svn-id: https://svn.apache.org/repos/asf/subversion/branches/1.8.x@1535275 13f79535-47bb-0310-9956-ffa450edef68