But this would not work(for syntax bug) until other modules change

1. divide into three block
2. change io port:
  broadcastUop -> fastUopsIn
  selectUop    -> fastUopOut
  extraPorts   -> slowPorts
  etc.
the cross sub block io is not wrapped, to it later

* should be compatible with single core difftest framework

dispatch,MemBlock: optimize fuType usages

When sbuffer checks if it is empty, it needs to check if sq is also empty
so there is no pending store. Errors will emerge rarely if we do not
check sq.

Fp load uses different wb port from int load for 2 reasons:
* Fp load needs recode, which is quite slow. We need one complete cycle
for recoding.
* Fp load data has nothing to do with int load data. There is no reason
to mix them together.

An extra recode stage (load_s3) is added for fp load, while int load will
still be writebackd at load_s2.