Hi,

This patch fixes AutoFDO Dejagnu tests to print relative filenames
instead of absolute ones when AutoFDO is unsupported. This is to
prevent spurious differences in dg-cmp-results.sh, like this:
  NA->UNSUPPORTED:
/home/yugr/src/gcc-57371/gcc/testsuite/g++.dg/bprob/g++-bprob-1.C
-fauto-profile
  UNSUPPORTED->NA:
/home/yugr/src/gcc/gcc/testsuite/g++.dg/bprob/g++-bprob-1.C
-fauto-profile

Ok for trunk?

-Y