Make autofdo tests safer for parallel builds

Make autofdo tests safer for parallel builds

There were some reports that the autofdo tests are non deterministic
with parallel builds. I wasn't able to reproduce this, but here are
two changes that may help:

- Always use unique file names for temporary files.
- Don't print file names in the test log because the directories
can vary (suggested by Jeff Law)

gcc/testsuite/:

2016-08-08  Andi Kleen  <ak@linux.intel.com>

	* lib/profopt.exp: (auto-profopt-execute): Don't include full
	test command line in failure log.
	(profopt-execute): dito. Make autofdo file names unique.

From-SVN: r239265