## TAC components

### Hardwares

Hardwares are used to modeling target device capabilities & also ops cost for
the target devices.

We have already modeled `cpu_hardware` & `gpu_hardware` as well as the
`nnapi_hardware`.

### Passes

#### Target Annotation Pass
In this pass, every op will be targeted with the user specified targets based on
the device capabilites. For example, If the user specified the desired targets