Revised patch to ensure that histograms from the profile summary are streamed

Revised patch to ensure that histograms from the profile summary are streamed
through the LTO files so that the working set can be computed for use in
downstream optimizations.

2012-11-30  Teresa Johnson  <tejohnson@google.com>

	* lto-cgraph.c (output_profile_summary): Stream out sum_all
	and histogram.
	(input_profile_summary): Stream in sum_all and histogram.
	(merge_profile_summaries): Merge sum_all and histogram, and
	change to use RDIV.
	(input_symtab): Call compute_working_sets after merging
	summaries.
	* gcov-io.c (gcov_histo_index): Make extern for compiler.
	* gcov-io.h (gcov_histo_index): Ditto.
	* profile.c (compute_working_sets): Remove static keyword.
	* profile.h (compute_working_sets): Ditto.
	* Makefile.in (lto-cgraph.o): Depend on profile.h.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@193999 138bc75d-0d04-0410-961f-82ee72b054a4