fix(bank_conflict): Selecting the oldest Load causes a conflict

[Anzooooo]

This modification changes load bank conflict from [default priority 0 1 2] to [so that the oldest Load does not have a bank conflict].

In the following, Load 0 refers to LoadUnit 0.

For example, before:
Load 0 lqidx 5
Load 1 lqidx 3
Load 2 lqidx 8
Assuming that three Loads have bank conflict, then we will default to making Load1 and Load2 have bank conflict so that they can be replayed.

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However, this may lead to deadlocks in some cases.
For example:
Load 0 robidx 7
Store 0 robidx 6
Load 1 robidx 5

Store 0 is dependent on Load 1 for data, while Load 0 is dependent on Store 0 for data, and Load 0 and Load 1 will have a bank conflict.
In this case then, Load 1 will Replay because of bank conflict and Load 0 will Replay because of forward fault(because of misalign).

---

With the modification, we will choose to make the oldest Load not generate bank conflict, thus circumventing the jamming problem.
Note !!! This may introduce performance fluctuations (up or down)

[XiangShanRobot]

[Generated by IPC robot]
commit: 27c4565

commit	astar	copy_and_run	coremark	gcc	gromacs	lbm	linux	mcf	microbench	milc	namd	povray	wrf	xalancbmk
27c4565	1.937	0.451	2.697	1.227	2.866	2.462	2.393	0.930	1.425	2.054	3.437	2.718	2.367	3.210

master branch:

commit	astar	copy_and_run	coremark	gcc	gromacs	lbm	linux	mcf	microbench	milc	namd	povray	wrf	xalancbmk
f346d72	1.899	0.450	2.701	1.219	2.833	2.461	2.395	0.921	1.426	2.022	3.432	2.707	2.368	3.227
d29ebcf	1.899	0.450	2.701	1.219	2.833	2.461	2.395	0.921	1.426	2.022	3.432	2.707	2.368	3.227
9cf1e44	1.899	0.450	2.701	1.219	2.833	2.461	2.395	0.921	1.426	2.022	3.432	2.707	2.368	3.227
98d2aaa	1.899	0.450	2.701	1.219	2.833	2.461	2.395	0.921	1.426	2.022	3.432	2.707	2.368	3.227
433cc30	1.899	0.450	2.701	1.219	2.833	2.461	2.395	0.921	1.426	2.022	3.432	2.707	2.368	3.227