Speed up use-after-scope (v2): rewrite into SSA

Speed up use-after-scope (v2): rewrite into SSA

2017-01-23  Martin Liska  <mliska@suse.cz>

	* asan.c (create_asan_shadow_var): New function.
	(asan_expand_poison_ifn): Likewise.
	* asan.h (asan_expand_poison_ifn): New declaration.
	* internal-fn.c (expand_ASAN_POISON): Likewise.
	* internal-fn.def (ASAN_POISON): New builtin.
	* sanopt.c (pass_sanopt::execute): Expand
	asan_expand_poison_ifn.
	* tree-inline.c (copy_decl_for_dup_finish): Make function
	external.
	* tree-inline.h (copy_decl_for_dup_finish): Likewise.
	* tree-ssa.c (is_asan_mark_p): New function.
	(execute_update_addresses_taken): Rewrite local variables
	(identified just by use-after-scope as addressable) into SSA.
2017-01-23  Martin Liska  <mliska@suse.cz>

	* gcc.dg/asan/use-after-scope-3.c: Add additional flags.
	* gcc.dg/asan/use-after-scope-9.c: Likewise and grep for
	sanopt optimization for ASAN_POISON.

From-SVN: r244791