[Bug] Missing post layernorm in CLIP model

[vincentccc]

🐛 Bug

I found clip model missing post_layernorm in forward, I tried to add post_layernorm, but I found there are some problem.

To Reproduce

Steps to reproduce the behavior:

If I use L:217, it will raise AttributeError: 'tuple' object has no attribute '_expr' If I use L:218, it will raise TypeError: Don't know how to handle type <class 'tvm.relax.frontend.nn.core.Tensor'>

Did I miss something? Wish to get some help, thanks a lot @MasterJH5574