* by default, snapshot will be saved every 10s

Tune compile options

* this can reduce the build time of the slow object files, which
  introduces little performance loss

* The -g option will generate debug information for every .cpp file.
  This information will be merged togather during linking, which is time
  consuming.

statistics.py: can count the number of lines of verilog code and log of each module

Unit-test: update code

Fix lsu store logic

Dev bpu rebase tage

BPU: fix s3 instrValid and s1 valid

Vga

Makefile: seed can be specified by SEED=6666

add tage logs

Brq: a branch instruction can only dequeue when roq commit it

ssh: remote no buffer