This tries to catch all cases where grub_cpu_to_XXX was used for constant
expressions (including sizeof).

	Just "packed" doesn't always pack the way we expect.

	Use GRUB_UTIL_FD_O_* rather than O_*.

	and remove export.h.

	open/read/write.

	condition.
	* grub-core/tests/fake_input.c: Likewise.
	* grub-core/tests/cmdline_cat_test.c: Likewise.

	than crashing.

and add it as source to functional_test module.