Extend the existing bprob and tree-prof tests to also run with autofdo.
The test runtimes are really a bit too short for autofdo, but it's
a reasonable sanity check.

This only works natively for now.

dejagnu doesn't seem to support a wrapper for unix tests, so I had
to open code running these tests.  That should be ok due to the
native run restrictions.

gcc/testsuite/:

2016-06-23  Andi Kleen  <ak@linux.intel.com>

	* g++.dg/bprob/bprob.exp: Support autofdo.
	* g++.dg/tree-prof/tree-prof.exp: dito.
	* gcc.dg/tree-prof/tree-prof.exp: dito.
	* gcc.misc-tests/bprob.exp: dito.
	* gfortran.dg/prof/prof.exp: dito.
	* lib/profopt.exp: dito.
	* lib/target-supports.exp: Check for autofdo.

From-SVN: r237732