rvinterf backslash escape: introduce libprint The new helper function library named libprint is meant to replace the badly misnamed libg23, and will soon contain functions for printing all of the same kinds of GPF TST packets that are now handled in libg23. However, we are also moving safe_print_trace() from libasync to this new library, and changing it to emit our new backslash escape format.

	.text
	.code	32
	.globl	strlen
strlen:
	mov	r1, r0
1:	ldrb	r2, [r0], #1
	cmn	r2, #0
	bne	1b
	sbc	r0, r0, r1
	bx	lr