draw/orcjit: supply stub function for tcs coro

This fixes a crash with shader cache enabled:
JIT session error: Unexpected definitions in module : [ draw_llvm_tcs_coro_variant ]
Failed to materialize symbols: { (draw_llvm_tcs_variant0_7, { draw_llvm_tcs_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/auxiliary/draw/draw_llvm.c

@@ -2968,6 +2968,7 @@ draw_tcs_llvm_generate(struct draw_llvm *llvm,
 
    if (gallivm->cache && gallivm->cache->data_size) {
       gallivm_stub_func(gallivm, variant_func);
+      gallivm_stub_func(gallivm, variant_coro);
       return;
    }