[aot] Workaround build structure to export GGUI symbols in libtaichi_export_core.so (#5870)
[aot] Workaround build structure to export GGUI symbols in libtaichi_export_core.so (#5870)

Porting this to libtaichi_export_core.so temporarily since we need to
migrate our texture demo to c-api after it's ready. Let's work
around it for now.
yuanming-hu/taichi,yuanming-hu/taichi,yuanming-hu/taichi,yuanming-hu/taichi