PR middle-end/39443
	* optabs.c (set_user_assembler_libfunc): New function.
	* expr.h (set_user_assembler_libfunc): New prototype.
	* c-common.c: Include libfuncs.h.
	(set_builtin_user_assembler_name): Call set_user_assembler_libfunc
	for memcmp, memset, memcpy, memmove and abort.
	* Makefile.in (c-common.o): Depend on libfuncs.h.

	* gcc.dg/pr39443.c: New test.

From-SVN: r144910