This patch enables the gcov-dump tool to optionally compute and dump

This patch enables the gcov-dump tool to optionally compute and dump
the working set information from the counter histogram, via a new -w option.
This is useful to help understand and tune how the compiler will use
the counter histogram, since it first computes the working set and selects
thresholds based on that.

This required moving the bulk of the compute_working_sets functionality
into gcov-io.c so that it was accessible by gcov-dump.c.

2013-04-03  Teresa Johnson  <tejohnson@google.com>

	* gcov-io.c (compute_working_sets): Moved most of body of old
        compute_working_sets here from profile.c.
	* gcov-io.h (NUM_GCOV_WORKING_SETS): Moved here from profile.c.
        (gcov_working_set_t): Moved typedef here from basic-block.h
        (compute_working_set): Declare.
	* profile.c (NUM_GCOV_WORKING_SETS): Moved to gcov-io.h.
	(get_working_sets): Renamed from compute_working_set,
        replace most of body with call to new compute_working_sets.
	(get_exec_counts): Replace call to compute_working_sets
        to get_working_sets.
	* profile.h (get_working_sets): Renamed from
        compute_working_set.
	* lto-cgraph.c (input_symtab): Replace call to compute_working_sets
        to get_working_sets.
	* basic-block.h (gcov_working_set_t): Moved to gcov-io.h.
	* gcov-dump.c (dump_working_sets): New function.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@197457 138bc75d-0d04-0410-961f-82ee72b054a4