The first of these, { "U-Boot", "^[B-Uo-t]*$", 0 }, would match
previously when the - and the letters were all interpreted literally.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>

Add some tests for the "drop wrong anchored optimization". Without
the previous commit, the first, fifth and seventh of these would fail,
i.e. those:

	{ "xby", "^a|b", 1},
	{ "", "x*$", 1},
	{ "yy", "x*$", 1},

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>

Inspecting the slre.c code reveals a few bugs; those are easy to
demonstrate with the new '=~' test operator. Before fixing them, let's
add a place to add test cases.

Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>