Admit additional `ADD` patterns in `GenTree:IsFieldAddr`.
Admit additional `ADD` patterns in `GenTree:IsFieldAddr`.

We already recognize `ADD(t, CNS_INT)` in this function. This change
extends the relevant logic to `ADD(CNS_INT, t)` iff the first operand is
a handle.

parjong/coreclr,botaberg/coreclr,kyulee1/coreclr,JonHanna/coreclr,rartemev/coreclr,JosephTremoulet/coreclr,yizhang82/coreclr,gkhanna79/coreclr,cydhaselton/coreclr,cydhaselton/coreclr,russellhadley/coreclr,ragmani/coreclr,mmitche/coreclr,botaberg/coreclr,ragmani/coreclr,wtgodbe/coreclr,gkhanna79/coreclr,ruben-ayrapetyan/coreclr,mmitche/coreclr,botaberg/coreclr,russellhadley/coreclr,cshung/coreclr,tijoytom/coreclr,kyulee1/coreclr,wtgodbe/coreclr,wateret/coreclr,AlexGhiondea/coreclr,yizhang82/coreclr,gkhanna79/coreclr,mskvortsov/coreclr,mmitche/coreclr,russellhadley/coreclr,ruben-ayrapetyan/coreclr,yizhang82/coreclr,ruben-ayrapetyan/coreclr,wtgodbe/coreclr,AlexGhiondea/coreclr,poizan42/coreclr,wateret/coreclr,poizan42/coreclr,dpodder/coreclr,poizan42/coreclr,mskvortsov/coreclr,krk/coreclr,JosephTremoulet/coreclr,russellhadley/coreclr,rartemev/coreclr,gkhanna79/coreclr,JosephTremoulet/coreclr,dpodder/coreclr,ragmani/coreclr,kyulee1/coreclr,JonHanna/coreclr,hseok-oh/coreclr,yizhang82/coreclr,cydhaselton/coreclr,russellhadley/coreclr,wateret/coreclr,wtgodbe/coreclr,poizan42/coreclr,dpodder/coreclr,JonHanna/coreclr,cshung/coreclr,hseok-oh/coreclr,poizan42/coreclr,mskvortsov/coreclr,JosephTremoulet/coreclr,botaberg/coreclr,cydhaselton/coreclr,parjong/coreclr,cshung/coreclr,AlexGhiondea/coreclr,ruben-ayrapetyan/coreclr,rartemev/coreclr,wtgodbe/coreclr,russellhadley/coreclr,ruben-ayrapetyan/coreclr,botaberg/coreclr,kyulee1/coreclr,rartemev/coreclr,mskvortsov/coreclr,krk/coreclr,wateret/coreclr,botaberg/coreclr,JonHanna/coreclr,AlexGhiondea/coreclr,hseok-oh/coreclr,JonHanna/coreclr,kyulee1/coreclr,mmitche/coreclr,AlexGhiondea/coreclr,parjong/coreclr,krk/coreclr,krk/coreclr,tijoytom/coreclr,cshung/coreclr,wateret/coreclr,dpodder/coreclr,tijoytom/coreclr,krk/coreclr,cydhaselton/coreclr,wtgodbe/coreclr,dpodder/coreclr,ragmani/coreclr,parjong/coreclr,wateret/coreclr,hseok-oh/coreclr,yizhang82/coreclr,yizhang82/coreclr,cshung/coreclr,mmitche/coreclr,tijoytom/coreclr,hseok-oh/coreclr,cshung/coreclr,ragmani/coreclr,parjong/coreclr,cydhaselton/coreclr,AlexGhiondea/coreclr,ruben-ayrapetyan/coreclr,gkhanna79/coreclr,gkhanna79/coreclr,poizan42/coreclr,tijoytom/coreclr,mskvortsov/coreclr,rartemev/coreclr,mskvortsov/coreclr,ragmani/coreclr,tijoytom/coreclr,parjong/coreclr,mmitche/coreclr,hseok-oh/coreclr,JosephTremoulet/coreclr,rartemev/coreclr,kyulee1/coreclr,krk/coreclr,JosephTremoulet/coreclr,dpodder/coreclr,JonHanna/coreclr