HPTW, RVH: add the flush function

[pxk27]

No description provided.

[XiangShanRobot]

[Generated by IPC robot]
commit: 0b6d077

commit	astar	copy_and_run	coremark	gcc	gromacs	lbm	linux	mcf	microbench	milc	namd	povray	wrf	xalancbmk
0b6d077	1.854	0.450	2.103	1.190	2.468	2.593	2.330	0.960	1.377	1.427	3.123	2.639	2.451	2.960

master branch:

commit	astar	copy_and_run	coremark	gcc	gromacs	lbm	linux	mcf	microbench	milc	namd	povray	wrf	xalancbmk
4b40434
9eee369									1.377
006b878								0.960	1.377
7299828
0c70648	1.854	0.450	2.103	1.190	2.468	2.593	2.330	0.960	1.377	1.427	3.123	2.639	2.451	2.960
b628978	1.854	0.450	2.103	1.190	2.468	2.593	2.329	0.960	1.377	1.427	3.123	2.639	2.451	2.960
5e237ba		0.450	2.103				2.328		1.377			2.639
363530d	1.841			1.190	2.478	2.597		0.961		1.391	3.126		2.452	2.959
a72b131
05d833a	1.854	0.450	2.103	1.190	2.468	2.593	2.330	0.961	1.377	1.427	3.123	2.639	2.451	2.960