Simplify gcov_histogram as it's used only for ARCS counters.

Simplify gcov_histogram as it's used only for ARCS counters.

2018-06-05  Martin Liska  <mliska@suse.cz>

	* auto-profile.c (read_autofdo_file): Do not use
	gcov_ctr_summary struct.
	(afdo_callsite_hot_enough_for_early_inline): Likewise.
	* coverage.c (struct counts_entry): Likewise.
	(read_counts_file): Read just single summary entry.
	(get_coverage_counts): Use gcov_summary struct.
	* coverage.h (get_coverage_counts): Likewise.
	* gcov-dump.c (dump_working_sets): Likewise.
	(tag_summary): Dump just single summary.
	* gcov-io.c (gcov_write_summary): Write just histogram
	summary.
	(gcov_read_summary): Read just single summary.
	(compute_working_sets): Use gcov_summary struct.
	* gcov-io.h (GCOV_TAG_SUMMARY_LENGTH): Remove usage
	of GCOV_COUNTERS_SUMMABLE.
	(GCOV_COUNTERS_SUMMABLE): Remove.
	(GCOV_FIRST_VALUE_COUNTER): Replace with
	GCOV_COUNTER_V_INTERVAL.
	(struct gcov_ctr_summary): Remove.
	(struct gcov_summary): Directly use fields of former
	gcov_ctr_summary.
	(compute_working_sets): Use gcov_summary struct.
	* gcov.c (read_count_file): Do not use ctrs fields.
	* lto-cgraph.c (merge_profile_summaries): Use gcov_summary
	struct.
	* lto-streamer.h (struct GTY): Make profile_info gcov_summary
	struct.
	* profile.c: Likewise.
	* profile.h: Likewise.
2018-06-05  Martin Liska  <mliska@suse.cz>

	* libgcov-driver.c (gcov_compute_histogram): Remove usage
	of gcov_ctr_summary.
	(compute_summary): Do it just for a single summary.
	(merge_one_data): Likewise.
	(merge_summary): Simplify as we read just single summary.
	(dump_one_gcov): Pass proper argument.
	* libgcov-util.c (compute_one_gcov): Simplify as we have just
	single summary.
	(gcov_info_count_all_cold): Likewise.
	(calculate_overlap): Likewise.

From-SVN: r261189