web-worker: Do not fail on bind re-init (#21854)
web-worker: Do not fail on bind re-init (#21854)

If a bind evaluator already exists for a given scope, allow it to be
re-constructed.

Fixes #17532
mhc-gh/amphtml,cory-work/amphtml,zhouyx/amphtml,adup-tech/amphtml,mhc-gh/amphtml,zhangsu/amphtml,alanorozco/amphtml,Gregable/amphtml,erwinmombay/amphtml,alanorozco/amphtml,nexxtv/amphtml,zhangsu/amphtml,cory-work/amphtml,mhc-gh/amphtml,Gregable/amphtml,src-code/amphtml,danielrozenberg/amphtml,taboola/amphtml,yandex-pcode/amphtml,jpettitt/amphtml,sharethrough/amphtml,src-code/amphtml,sharethrough/amphtml,erwinmombay/amphtml,nexxtv/amphtml,prateekbh/amphtml,Gregable/amphtml,prateekbh/amphtml,jridgewell/amphtml,lannka/amphtml,jridgewell/amphtml,sharethrough/amphtml,Gregable/amphtml,sharethrough/amphtml,voyagegroup/amphtml,danielrozenberg/amphtml,zhangsu/amphtml,erwinmombay/amphtml,tlong2/amphtml,adup-tech/amphtml,zhouyx/amphtml,jpettitt/amphtml,media-net/amphtml,taboola/amphtml,taboola/amphtml,cory-work/amphtml,jmadler/amphtml,alanorozco/amphtml,nexxtv/amphtml,rsimha-amp/amphtml,jridgewell/amphtml,prateekbh/amphtml,danielrozenberg/amphtml,src-code/amphtml,jpettitt/amphtml,dotandads/amphtml,Gregable/amphtml,src-code/amphtml,media-net/amphtml,danielrozenberg/amphtml,tlong2/amphtml,jridgewell/amphtml,ampproject/amphtml,yandex-pcode/amphtml,ampproject/amphtml,zhouyx/amphtml,src-code/amphtml,lannka/amphtml,tlong2/amphtml,cory-work/amphtml,zhangsu/amphtml,rsimha-amp/amphtml,alanorozco/amphtml,src-code/amphtml,ampproject/amphtml,yandex-pcode/amphtml,mhc-gh/amphtml,smartadserver/amphtml,tlong2/amphtml,media-net/amphtml,jpettitt/amphtml,jpettitt/amphtml,voyagegroup/amphtml,prateekbh/amphtml,voyagegroup/amphtml,nexxtv/amphtml,sharethrough/amphtml,ampproject/amphtml,zhouyx/amphtml,smartadserver/amphtml,Gregable/amphtml,danielrozenberg/amphtml,yandex-pcode/amphtml,rsimha-amp/amphtml,yandex-pcode/amphtml,erwinmombay/amphtml,tlong2/amphtml,cory-work/amphtml,Gregable/amphtml,zhouyx/amphtml,voyagegroup/amphtml,smartadserver/amphtml,jmadler/amphtml,danielrozenberg/amphtml,prateekbh/amphtml,media-net/amphtml,ampproject/amphtml,voyagegroup/amphtml,mhc-gh/amphtml,lannka/amphtml,jmadler/amphtml,rsimha-amp/amphtml,media-net/amphtml,dotandads/amphtml,media-net/amphtml,media-net/amphtml,honeybadgerdontcare/amphtml,alanorozco/amphtml,adup-tech/amphtml,taboola/amphtml,jridgewell/amphtml,smartadserver/amphtml,tlong2/amphtml,lannka/amphtml,prateekbh/amphtml,smartadserver/amphtml,rsimha-amp/amphtml,honeybadgerdontcare/amphtml,adup-tech/amphtml,prateekbh/amphtml,jmadler/amphtml,danielrozenberg/amphtml,zhangsu/amphtml,dotandads/amphtml,zhangsu/amphtml,mhc-gh/amphtml,rsimha-amp/amphtml,jridgewell/amphtml,sharethrough/amphtml,lannka/amphtml,erwinmombay/amphtml,jridgewell/amphtml,honeybadgerdontcare/amphtml,zhouyx/amphtml,alanorozco/amphtml,jpettitt/amphtml,dotandads/amphtml,rsimha-amp/amphtml,taboola/amphtml,alanorozco/amphtml,lannka/amphtml,nexxtv/amphtml,adup-tech/amphtml,ampproject/amphtml,erwinmombay/amphtml,honeybadgerdontcare/amphtml,ampproject/amphtml,ampproject/amphtml,Gregable/amphtml,jpettitt/amphtml,mhc-gh/amphtml,dotandads/amphtml,yandex-pcode/amphtml,honeybadgerdontcare/amphtml,taboola/amphtml,dotandads/amphtml,nexxtv/amphtml,mhc-gh/amphtml,jpettitt/amphtml,nexxtv/amphtml,cory-work/amphtml,danielrozenberg/amphtml,honeybadgerdontcare/amphtml,media-net/amphtml,adup-tech/amphtml,cory-work/amphtml,taboola/amphtml,voyagegroup/amphtml,honeybadgerdontcare/amphtml,lannka/amphtml,zhouyx/amphtml,yandex-pcode/amphtml,alanorozco/amphtml,voyagegroup/amphtml,jmadler/amphtml,jmadler/amphtml,smartadserver/amphtml