Catch the FileNotFoundException when to get the obsolete attribute for type. (#27389)
Catch the FileNotFoundException when to get the obsolete attribute for type. (#27389)

* Catch the FileNotFoundException when to get the obsolete attribute for type.

* Move continue out of if.

* Add some comments.

* Update the comments.

BrennanConroy/corefx,ptoonen/corefx,ericstj/corefx,zhenlan/corefx,wtgodbe/corefx,shimingsg/corefx,ViktorHofer/corefx,ViktorHofer/corefx,ptoonen/corefx,mmitche/corefx,shimingsg/corefx,mmitche/corefx,ericstj/corefx,Jiayili1/corefx,Jiayili1/corefx,ericstj/corefx,zhenlan/corefx,wtgodbe/corefx,shimingsg/corefx,ptoonen/corefx,ptoonen/corefx,ViktorHofer/corefx,mmitche/corefx,Jiayili1/corefx,ViktorHofer/corefx,zhenlan/corefx,mmitche/corefx,ericstj/corefx,wtgodbe/corefx,ViktorHofer/corefx,ViktorHofer/corefx,shimingsg/corefx,Jiayili1/corefx,wtgodbe/corefx,BrennanConroy/corefx,ptoonen/corefx,wtgodbe/corefx,zhenlan/corefx,ericstj/corefx,zhenlan/corefx,zhenlan/corefx,ViktorHofer/corefx,mmitche/corefx,ptoonen/corefx,ericstj/corefx,wtgodbe/corefx,mmitche/corefx,Jiayili1/corefx,wtgodbe/corefx,zhenlan/corefx,shimingsg/corefx,ptoonen/corefx,BrennanConroy/corefx,Jiayili1/corefx,ericstj/corefx,mmitche/corefx,shimingsg/corefx,shimingsg/corefx,Jiayili1/corefx