llvmpipe/cs/orcjit: add stub function name for coro

This fixes some debug
JIT session error: Unexpected definitions in module : [ cs_co_variant ]
Failed to materialize symbols: { (cs0_variant0_3, { cs_variant }) }

Fixes: bb0efdd4d8 ("llvmpipe: add shader cache support for ORCJIT implementation")
Reviewed-by: Icenowy Zheng <uwu@icenowy.me>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30335>

src/gallium/drivers/llvmpipe/lp_state_cs.c

@@ -411,6 +411,7 @@ generate_compute(struct llvmpipe_context *lp,
 
    if (variant->gallivm->cache->data_size) {
       gallivm_stub_func(gallivm, function);
+      gallivm_stub_func(gallivm, coro);
       return;
    }