kk: Clamp negative array indices to 0

Required so that uint array formats don't incorrectly wrap to last array
slice instead of the first one. For some reason this only happens with
uint texture formats while int and float formats work as expected.

Acked-by: Arcady Goldmints-Orlov <arcady@lunarg.com>
Signed-off-by: Aitor Camacho <aitor@lunarg.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/38713>

src/kosmickrisp/compiler/nir_to_msl.c

@@ -614,12 +614,12 @@ round_src_component_to_uint(struct nir_to_msl_ctx *ctx, nir_src *src,
 {
    bool is_float = msl_src_is_float(ctx, src);
    if (is_float) {
-      P(ctx, "uint(rint(");
+      P(ctx, "uint(max(int(rint(");
    }
    src_to_msl(ctx, src);
    P(ctx, ".%c", component);
    if (is_float) {
-      P(ctx, "))");
+      P(ctx, ")), int(0)))");
    }
 }