pan/bi: bail from optimizing on oom

Allocations can fail, and since this is an optimization pass, let's just
skip the pass and let some other code deal with the OOM situation.

Fixes: 800a861431 ("pan/bi: Fuse FCMP/ICMP on Valhall")
Reviewed-by: Eric R. Smith <eric.smith@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/36724>

src/panfrost/compiler/valhall/va_optimize.c

@@ -306,6 +306,9 @@ va_optimize_forward(bi_context *ctx)
    bi_instr **uses = calloc(count, sizeof(*uses));
    BITSET_WORD *multiple = calloc(BITSET_WORDS(count), sizeof(*multiple));
 
+   if (!lut || !uses || !multiple)
+      goto out;
+
    /* Record usage across blocks */
    bi_foreach_block(ctx, block) {
       bi_foreach_instr_in_block(block, I) {
@@ -323,6 +326,7 @@ va_optimize_forward(bi_context *ctx)
       va_fuse_cmp(ctx, lut, multiple, I);
    }
 
+out:
    free(uses);
    free(lut);
    free(multiple);