ARM-CI : Use archived root-fs and run tests with --sequential option (#7946)
ARM-CI : Use archived root-fs and run tests with --sequential option (#7946)

* ARM-CI : Use archived root-fs and run tests with --sequential option

To make sure the reason of test failure ramdomly( #6298 ),
We checked segmentation faults occurred from mounted rootfs and the multi thread processing.

So I changed root-fs to archived root-fs and run tests with --sequential option.

* change to original clang version

poizan42/coreclr,JonHanna/coreclr,gkhanna79/coreclr,AlexGhiondea/coreclr,poizan42/coreclr,ragmani/coreclr,wtgodbe/coreclr,kyulee1/coreclr,pgavlin/coreclr,hseok-oh/coreclr,sjsinju/coreclr,neurospeech/coreclr,cydhaselton/coreclr,sagood/coreclr,kyulee1/coreclr,botaberg/coreclr,AlexGhiondea/coreclr,yeaicc/coreclr,mskvortsov/coreclr,hseok-oh/coreclr,AlexGhiondea/coreclr,AlexGhiondea/coreclr,gkhanna79/coreclr,gkhanna79/coreclr,yeaicc/coreclr,wateret/coreclr,JosephTremoulet/coreclr,botaberg/coreclr,wateret/coreclr,botaberg/coreclr,mskvortsov/coreclr,wateret/coreclr,JosephTremoulet/coreclr,AlexGhiondea/coreclr,JonHanna/coreclr,yeaicc/coreclr,James-Ko/coreclr,wtgodbe/coreclr,pgavlin/coreclr,neurospeech/coreclr,cshung/coreclr,kyulee1/coreclr,tijoytom/coreclr,mskvortsov/coreclr,dpodder/coreclr,ragmani/coreclr,poizan42/coreclr,poizan42/coreclr,dpodder/coreclr,gkhanna79/coreclr,hseok-oh/coreclr,dpodder/coreclr,cydhaselton/coreclr,James-Ko/coreclr,mskvortsov/coreclr,ruben-ayrapetyan/coreclr,James-Ko/coreclr,cmckinsey/coreclr,pgavlin/coreclr,JonHanna/coreclr,JosephTremoulet/coreclr,cmckinsey/coreclr,cmckinsey/coreclr,rartemev/coreclr,parjong/coreclr,yizhang82/coreclr,poizan42/coreclr,mmitche/coreclr,James-Ko/coreclr,YongseopKim/coreclr,botaberg/coreclr,parjong/coreclr,hseok-oh/coreclr,sagood/coreclr,krytarowski/coreclr,neurospeech/coreclr,ragmani/coreclr,YongseopKim/coreclr,krk/coreclr,tijoytom/coreclr,tijoytom/coreclr,parjong/coreclr,James-Ko/coreclr,krk/coreclr,qiudesong/coreclr,ruben-ayrapetyan/coreclr,botaberg/coreclr,alexperovich/coreclr,yizhang82/coreclr,mmitche/coreclr,cydhaselton/coreclr,wtgodbe/coreclr,sjsinju/coreclr,botaberg/coreclr,cmckinsey/coreclr,mskvortsov/coreclr,jamesqo/coreclr,krytarowski/coreclr,sagood/coreclr,neurospeech/coreclr,krytarowski/coreclr,sjsinju/coreclr,cmckinsey/coreclr,russellhadley/coreclr,rartemev/coreclr,krytarowski/coreclr,russellhadley/coreclr,russellhadley/coreclr,poizan42/coreclr,wtgodbe/coreclr,parjong/coreclr,jamesqo/coreclr,yizhang82/coreclr,sagood/coreclr,kyulee1/coreclr,tijoytom/coreclr,wateret/coreclr,russellhadley/coreclr,pgavlin/coreclr,yizhang82/coreclr,ruben-ayrapetyan/coreclr,tijoytom/coreclr,qiudesong/coreclr,mmitche/coreclr,ruben-ayrapetyan/coreclr,krk/coreclr,gkhanna79/coreclr,yeaicc/coreclr,hseok-oh/coreclr,James-Ko/coreclr,YongseopKim/coreclr,YongseopKim/coreclr,rartemev/coreclr,pgavlin/coreclr,tijoytom/coreclr,qiudesong/coreclr,russellhadley/coreclr,JonHanna/coreclr,neurospeech/coreclr,russellhadley/coreclr,yeaicc/coreclr,krk/coreclr,cshung/coreclr,mmitche/coreclr,YongseopKim/coreclr,JonHanna/coreclr,mskvortsov/coreclr,krk/coreclr,wtgodbe/coreclr,ruben-ayrapetyan/coreclr,rartemev/coreclr,yeaicc/coreclr,cshung/coreclr,cmckinsey/coreclr,cydhaselton/coreclr,cydhaselton/coreclr,dpodder/coreclr,alexperovich/coreclr,jamesqo/coreclr,JonHanna/coreclr,YongseopKim/coreclr,jamesqo/coreclr,alexperovich/coreclr,cydhaselton/coreclr,qiudesong/coreclr,sagood/coreclr,ragmani/coreclr,ragmani/coreclr,cmckinsey/coreclr,krytarowski/coreclr,neurospeech/coreclr,JosephTremoulet/coreclr,sagood/coreclr,sjsinju/coreclr,kyulee1/coreclr,qiudesong/coreclr,dpodder/coreclr,alexperovich/coreclr,alexperovich/coreclr,yizhang82/coreclr,cshung/coreclr,jamesqo/coreclr,yizhang82/coreclr,dpodder/coreclr,qiudesong/coreclr,mmitche/coreclr,yeaicc/coreclr,gkhanna79/coreclr,wtgodbe/coreclr,krytarowski/coreclr,sjsinju/coreclr,pgavlin/coreclr,sjsinju/coreclr,cshung/coreclr,rartemev/coreclr,parjong/coreclr,AlexGhiondea/coreclr,kyulee1/coreclr,cshung/coreclr,ragmani/coreclr,mmitche/coreclr,JosephTremoulet/coreclr,alexperovich/coreclr,wateret/coreclr,jamesqo/coreclr,ruben-ayrapetyan/coreclr,rartemev/coreclr,JosephTremoulet/coreclr,parjong/coreclr,hseok-oh/coreclr,krk/coreclr,wateret/coreclr