autofdo create_gcov uses a lot of memory for large sample files.
Since gcc runs quite long the sample files generated during
the bootstrap are fairly ig.

Currently I can't even build make autoprofiledbootstrap on my system at
home because create_gcov needs more than 12GB and runs out of memory.

This should probably be fixed in create_gcov, but for now
lowering the sampling rate works well enough for me. The bootstrap
run is long enough that it gets good enough data in any case.

gcc/:
2019-01-14  Andi Kleen  <ak@linux.intel.com>

	* Makefile.in: Lower autofdo sampling rate by 10x.
	* Makefile.tpl: Dito.

From-SVN: r267930