MainPipe: set `full_overwrite` when each byte in store is masked

[XiangShanRobot]

[Generated by IPC robot] commit: e4da508fcb172f8f8a22712ff48fb60512b3d15b	commit	astar	copy_and_run	coremark	gcc	gromacs	lbm	linux	mcf	microbench	milc	namd	povray	wrf	xalancbmk
e4da508	1.823	0.448	2.048	1.178	2.953	2.504	2.291	0.930	1.381	1.372	3.445	2.655	2.397	2.944

master branch:	commit	astar	copy_and_run	coremark	gcc	gromacs	lbm	linux	mcf	microbench	milc	namd	povray	wrf	xalancbmk
0f42355			2.060	1.199				0.932	1.419		3.427			2.932
95e6033			2.060	1.199	2.938	2.508		0.932	1.419	1.338	3.427			2.932
58cb1b0	1.822		2.060	1.180	2.944	2.503		0.932	1.419	1.328	3.437		2.399	2.931
202ef6b	1.815	0.448	2.060	1.182	2.953	2.504	2.291	0.930	1.403	1.319	3.426	2.660	2.397	2.940
4c46d75	1.815	0.448	2.060	1.182	2.953	2.504	2.291	0.930	1.403	1.319	3.426	2.660	2.397	2.940
807e518	1.815	0.448	2.060	1.182	2.953	2.504	2.291	0.930	1.403	1.319	3.426	2.660	2.397	2.940
5820cff	1.815	0.448	2.060	1.182	2.953	2.504	2.291	0.930	1.403	1.319	3.426	2.660	2.397	2.940
8daac0b
c41a9f7
31fae68	1.815	0.448	2.060	1.182	2.953	2.504	2.291	0.930	1.403	1.319	3.426	2.660	2.397	2.940