vfalu: Use oldVd as input to mgu in last Uop for vfred inst

[sinceforYy]

No description provided.

[XiangShanRobot]

[Generated by IPC robot]
commit: c566e23

commit	astar	copy_and_run	coremark	gcc	gromacs	lbm	linux	mcf	microbench	milc	namd	povray	wrf	xalancbmk
c566e23	1.808	0.447	2.043	1.187	2.938	2.508	2.291	0.921	1.369	1.441	3.454	2.658	2.399	2.932

master branch:

commit	astar	copy_and_run	coremark	gcc	gromacs	lbm	linux	mcf	microbench	milc	namd	povray	wrf	xalancbmk
a7828dc
9f598f8
e975de6	1.808	0.447	2.043	1.187	2.938	2.508	2.291	0.921	1.369	1.441	3.454	2.658	2.399	2.932
ff9b84b		0.447	2.043	1.187			2.291	0.921	1.369		3.454	2.658		2.932
3bec463	1.808	0.447	2.043	1.187	2.938	2.508	2.291	0.921	1.369	1.441	3.454	2.658	2.399	2.932
2d12882		0.447	2.043	1.187			2.291	0.921	1.369		3.454	2.658		2.932
ef14270	1.827	0.448	2.048	1.190	2.938	2.508	2.289	0.932	1.369	1.410	3.445	2.672	2.398	2.932
5c5f442	1.827	0.448	2.048	1.190	2.938	2.508	2.289	0.932	1.369	1.410	3.445	2.672	2.398	2.932
d67c873	1.827	0.448	2.048	1.190	2.938	2.508	2.289	0.932	1.369	1.410	3.445	2.672	2.398	2.932