[hack] Support list assignment for Tabstract of a vector
[hack] Support list assignment for Tabstract of a vector

Summary: If a Vector or a Pair is wrapped in a ##Tabstract## (either a generic, newtype,
or type constant), then the assignment will fail even though we allow this for
the Vector and Pair type.

This fixes that case.

Reviewed By: @jwatzman

Differential Revision: D2226799

cesarandreu/flow,OCamlPro/flow,CJstar/flow,samwgoldman/flow,KevinTCoughlin/flow,nmote/flow,popham/flow,chenglou/flow,jeffutter/flow,mroch/flow,chenglou/flow,YelaSeamless/flow,shiftcars/flow,chenglou/flow,AgentME/flow,Wanderfalke/flow,mroch/flow,claudiopro/flow,matklad/flow,JohnyDays/flow,MichaelDeBoey/flow,shiftcars/flow,YelaSeamless/flow,jgrund/flow,OCamlPro/flow,facebook/flow,rafaelstz/flow,JohnyDays/flow,Fresheyeball/flow,JeckoHeroOrg/flow,mcanthony/flow-type,chenglou/flow,nmote/flow,matklad/flow,CJstar/flow,TiddoLangerak/flow,JonathanUsername/flow,shiftcars/flow,AprilArcus/flow,ylu1317/flow,matklad/flow,d14b3l/flow,ylu1317/flow,facebook/flow,lyip1992/flow,JohnyDays/flow,claudiopro/flow,claudiopro/flow,d14b3l/flow,danvk/flow,paulshen/flow,JeckoHeroOrg/flow,jgrund/flow,jdelStrother/flow,facebook/flow,jamesgpearce/flow,AprilArcus/flow,ForbesLindesay/flow,fletcherw/flow,lyip1992/flow,ylu1317/flow,KevinTCoughlin/flow,jgrund/flow,MichaelDeBoey/flow,Wanderfalke/flow,YelaSeamless/flow,danvk/flow,graue/flow,MichaelDeBoey/flow,AprilArcus/flow,asivitz/flow,davidmason/flow,dv/flow,fletcherw/flow,gabro/flow,darioajr/flow,CJstar/flow,d14b3l/flow,nmote/flow,popham/flow,jeffmo/flow,jeffutter/flow,graue/flow,cesarandreu/flow,YelaSeamless/flow,MichaelDeBoey/flow,cesarandreu/flow,popham/flow,jdelStrother/flow,AgentME/flow,facebook/flow,Drooids/flow,JonathanUsername/flow,jamesgpearce/flow,Fresheyeball/flow,jeffmo/flow,mroch/flow,asivitz/flow,Wanderfalke/flow,popham/flow,lyip1992/flow,JeckoHeroOrg/flow,graue/flow,graue/flow,facebook/flow,jeffutter/flow,dv/flow,jgrund/flow,darioajr/flow,Eyyub/flow,gabelevi/flow,OCamlPro/flow,nmote/flow,OCamlPro/flow,mcanthony/flow-type,mcanthony/flow-type,darioajr/flow,jdelStrother/flow,asivitz/flow,ylu1317/flow,gabelevi/flow,d14b3l/flow,claudiopro/flow,mroch/flow,d14b3l/flow,facebook/flow,JonathanUsername/flow,samwgoldman/flow,jeffmo/flow,matklad/flow,JonathanUsername/flow,ianobermiller/flow,gabelevi/flow,ianobermiller/flow,AgentME/flow,nmote/flow,paulshen/flow,ForbesLindesay/flow,jdelStrother/flow,AgentME/flow,siddhartharay007/flow,gabelevi/flow,asivitz/flow,jamesgpearce/flow,paulshen/flow,jamesgpearce/flow,Eyyub/flow,TiddoLangerak/flow,popham/flow,ianobermiller/flow,rafaelstz/flow,samwgoldman/flow,ianobermiller/flow,samwgoldman/flow,rafaelstz/flow,JonathanUsername/flow,siddhartharay007/flow,facebook/flow,samwgoldman/flow,gabro/flow,samwgoldman/flow,gabro/flow,dv/flow,Fresheyeball/flow,JohnyDays/flow,davidmason/flow,dv/flow,gabro/flow,ForbesLindesay/flow,jgrund/flow,fletcherw/flow,mroch/flow,graue/flow,davidmason/flow,davidmason/flow,jamesgpearce/flow,claudiopro/flow,TiddoLangerak/flow,JonathanUsername/flow,chenglou/flow,davidmason/flow,Drooids/flow,gabro/flow,JeckoHeroOrg/flow,d14b3l/flow,ForbesLindesay/flow,TiddoLangerak/flow,rafaelstz/flow,samwgoldman/flow,gabelevi/flow,popham/flow,JeckoHeroOrg/flow,jdelStrother/flow,jeffmo/flow,jeffutter/flow,Fresheyeball/flow,ForbesLindesay/flow,popham/flow,mroch/flow,jeffmo/flow,AprilArcus/flow,fletcherw/flow,MichaelDeBoey/flow,Eyyub/flow,nmote/flow,lyip1992/flow,jdelStrother/flow,danvk/flow,darioajr/flow,KevinTCoughlin/flow,CJstar/flow,siddhartharay007/flow,mroch/flow,cesarandreu/flow,fletcherw/flow,shiftcars/flow,danvk/flow,gabro/flow,matklad/flow,Drooids/flow,ylu1317/flow,AprilArcus/flow,chenglou/flow,nmote/flow,shiftcars/flow,Wanderfalke/flow,YelaSeamless/flow,jeffmo/flow,graue/flow,mcanthony/flow-type,jgrund/flow,jamesgpearce/flow,Drooids/flow,TiddoLangerak/flow,gabelevi/flow,siddhartharay007/flow,paulshen/flow,KevinTCoughlin/flow,JonathanUsername/flow,shiftcars/flow,Eyyub/flow,gabelevi/flow,jamesgpearce/flow,AprilArcus/flow,fletcherw/flow,rafaelstz/flow,AgentME/flow,ForbesLindesay/flow