PR sanitizer/78832
	* sanopt.c (sanitize_asan_mark_unpoison): Remove next variable, use
	continue if gsi_next should be skipped.
	(sanitize_asan_mark_poison): Remove prev variable, use continue if
	gsi_prev should be skipped.  When removing ASAN_MARK, do gsi_prev
	first and gsi_remove on a previously made copy of the iterator.

	* gcc.dg/asan/pr78832.c: New test.

From-SVN: r243777