Add a compatibility header for CentOS/RHEL 6
Add a compatibility header for CentOS/RHEL 6

Signed-off-by: Andrew Fernandes <02e0a999c50b1f88df7a8f5a04e1b76b35ea6a88@fernandes.org>

maxamillion/runc,crosbymichael/runc,ZJU-SEL/runc,justincormack/runc,mYmNeo/runc,maxamillion/runc,kolyshkin/runc,shishir-a412ed/runc,cloudfoundry-incubator/runc,laijs/runc,adrianreber/runc,wking/runc,kolyshkin/runc,vbatts/runc,keloyang/runc,estesp/runc,sunyuan3/runc,estesp/runc,stefanberger/runc,rajasec/runc,hqhq/runc,inatatsu/runc,WeiZhang555/runc,keloyang/runc,wking/runc,rajasec/runc,rhatdan/runc,shishir-a412ed/runc,sunyuan3/runc,ZJU-SEL/runc,stefanberger/runc,docker/runc,inatatsu/runc,albertoleal/runc,hqhq/runc,stefanberger/runc,wangkirin/runc,opencontainers/runc,xiaochenshen/runc,vbatts/runc,adrianreber/runc,xiaochenshen/runc,wangkirin/runc,rhatdan/runc,rhatdan/runc,jhowardmsft/runc,laijs/runc,avagin/runc,mheon/runc,avagin/runc,kimh/runc,opencontainers/runc,kimh/runc,coolljt0725/runc,shishir-a412ed/runc,albertoleal/runc,kolyshkin/runc,mheon/runc,keloyang/runc,jhowardmsft/runc,jhowardmsft/runc,hqhq/runc,albertoleal/runc,maxamillion/runc,dqminh/runc,nkwilson/runc,WeiZhang555/runc,cyphar/runc,runcom/runc,inatatsu/runc,justincormack/runc,dqminh/runc,docker/runc,rhatdan/runc,abduld/runc,opencontainers/runc,laijs/runc,dqminh/runc,avagin/runc,kolyshkin/runc,wangkirin/runc,kimh/runc,crosbymichael/runc,estesp/runc,rajasec/runc,ZJU-SEL/runc,cyphar/runc,dqminh/runc,cloudfoundry-incubator/runc,vbatts/runc,abduld/runc,runcom/runc,docker/runc,coolljt0725/runc,cloudfoundry-incubator/runc,mikebrow/runc,opencontainers/runc,mheon/runc,mYmNeo/runc,justincormack/runc,sunyuan3/runc,nkwilson/runc,nkwilson/runc,runcom/runc,cyphar/runc,adrianreber/runc,mikebrow/runc,WeiZhang555/runc,mikebrow/runc,wking/runc,coolljt0725/runc,mYmNeo/runc,abduld/runc,xiaochenshen/runc,crosbymichael/runc