From: @dayschan
Reviewed-by: @ckey_dou,@gaoxiong1
Signed-off-by: @gaoxiong1

From: @jiaoy1224
Reviewed-by: @gaoxiong1,@gaoxiong1,@ckey_dou
Signed-off-by: @ckey_dou

From: @wenfangpei
Reviewed-by: @gaoxiong1,@ckey_dou
Signed-off-by: @ckey_dou

From: @wenfangpei
Reviewed-by: @gaoxiong1,@ckey_dou,@gaoxiong1,@ckey_dou
Signed-off-by: @ckey_dou,@ckey_dou

From: @tronzhang
Reviewed-by: @gaoxiong1,@ckey_dou
Signed-off-by: @ckey_dou

Use a disjoint-set to maintain the clusters before building anf-graph, to speed up the process of building graph.
Dump the change of nodes to file if the graphkernel flag "dump_as_text" is set.

The algorithm of CheckCircle is unchanged.
Reuse the FuseNodesToSubGraph interface.

From: @lianliguang
Reviewed-by: @jjfeing,@zhoufeng54
Signed-off-by: @zhoufeng54

From: @zuochuanyong
Reviewed-by: @zhaizhiqiang,@guoqi1024,@zhoufeng54
Signed-off-by: @zhaizhiqiang

From: @wenfangpei
Reviewed-by: @ckey_dou,@gaoxiong1
Signed-off-by: @ckey_dou

From: @lingyunli63
Reviewed-by: @ckey_dou,@gaoxiong1
Signed-off-by: @gaoxiong1

From: @r1chardf1d0
Reviewed-by: @gaoxiong1,@ckey_dou
Signed-off-by: @ckey_dou

From: @wenfangpei
Reviewed-by: @gaoxiong1,@ckey_dou
Signed-off-by: @ckey_dou

From: @zengzitao
Reviewed-by: @ckey_dou,@gaoxiong1
Signed-off-by: @gaoxiong1

From: @wenfangpei
Reviewed-by: @gaoxiong1,@ckey_dou
Signed-off-by: @ckey_dou

From: @TFbunny
Reviewed-by: @tom__chen,@robingrosman
Signed-off-by: @robingrosman

From: @looop5
Reviewed-by: @gaoxiong1,@ckey_dou
Signed-off-by: @ckey_dou

From: @erpim
Reviewed-by: 
Signed-off-by:

From: @Margaret_wangrui
Reviewed-by: @hwhewei,@zh_qh
Signed-off-by: @zh_qh

fix compiling

From: @jjfeing
Reviewed-by: @zhoufeng54,@kisnwang
Signed-off-by: @kisnwang

From: @liu_xiao_93
Reviewed-by: @zhoufeng54,@jjfeing
Signed-off-by: @jjfeing

From: @jjfeing
Reviewed-by: @kisnwang,@zhoufeng54
Signed-off-by: @zhoufeng54

From: @hwhewei
Reviewed-by: @zh_qh,@ginfung
Signed-off-by: @zh_qh

From: @looop5
Reviewed-by: @gaoxiong1,@dylangeng
Signed-off-by: @dylangeng

From: @Margaret_wangrui
Reviewed-by: @ginfung,@zh_qh
Signed-off-by: @zh_qh

From: @lingyunli63
Reviewed-by: @gaoxiong1,@anyrenwei
Signed-off-by: @anyrenwei

From: @zengzitao
Reviewed-by: @gaoxiong1,@anyrenwei
Signed-off-by: @anyrenwei

From: @wilfchen
Reviewed-by: @cristoval,@limingqi107
Signed-off-by: @limingqi107