We need to asynchronous reset the system when reset is true.
In verilator model, it's done by always resetting the external devices when reset is true.
After the reset signal is released, we call init once for external devices to make sure they are correctly reset.

This reverts commit a0ffea30.

Case: vvvdvvvddddd
            ^    ^
If the leftmost instruction is a store and it writebacks, these instructions won't be replayed.
However, we cannot move headPtr to the left hand side of the dispatchPtr since there're still
instructions that have not been dispatched to issue queues.
In this case, we only remove the instructions before dispatchPtr.
Moving headPtr in case of store writeback only affects performance, since instructions leave dispatch queue when they commit.

* It will help NEMU force IPF treat cross-page IPF correctly

Futher we will support store queue size that is not power of 2.
However, currently there're still bugs.

BlockInclusiveCache always responds with a GrantData even for BtoT.

Or we will trigger an assertion in s_resp state.

* It will help NEMU force IPF treat cross-page IPF correctly

This reverts commit f7bed381.

probe.

test_gen_0             test_gen_1
    |                      |
   \ /                    \ /
    L1                     L1
    |                      |
   \ /                    \ /
    L2                     L2
     \                    /
      \                  /
       \                /
        \              /
         \            /
               L3