PR c/78408
	* tree-ssa-ccp.c: Include tree-dfa.h.
	(optimize_memcpy): New function.
	(pass_fold_builtins::execute): Use it.  Remove useless conditional
	break after BUILT_IN_VA_*.

	* gcc.dg/pr78408-1.c: New test.
	* gcc.dg/pr78408-2.c: New test.

From-SVN: r243753