Fix handling of GUESSED_LOCAL in auto-fdo and preserve more static profile

Fix handling of GUESSED_LOCAL in auto-fdo and preserve more static profile

This patch fixes ICE where GUESSED_LOCAL was kept in autofdo profile.
It may make more sense to turn GESSED_LOCAL 0 to GUESSED 0 since it seems
bit more informative then autofdo 0 (which really means that count is below
the 2% threshold or that info was lost due to some code transformation).

The patch also modifies code setting probabilities of edge to keep reliable
predictions of 0 or 1.

gcc/ChangeLog:

	* auto-profile.cc (update_count_by_afdo_count): Fix handling
	of GUESSED_LOCAL.
	(afdo_calculate_branch_prob): Preserve static profile for
	probabilities 0 and 1.