[Ast differ] Add type parameter instantiation test
[Ast differ] Add type parameter instantiation test

Summary: The test added here is to show the difference of the subsequent commit.

Reviewed By: nmote, dsainati1

Differential Revision: D10282326

fbshipit-source-id: 94d169e4f5011d70020afba99c96c87d1bccf746

jamesgpearce/flow,AgentME/flow,facebook/flow,jamesgpearce/flow,popham/flow,gabelevi/flow,mroch/flow,gabelevi/flow,popham/flow,popham/flow,samwgoldman/flow,jamesgpearce/flow,facebook/flow,jamesgpearce/flow,mroch/flow,samwgoldman/flow,popham/flow,jamesgpearce/flow,mroch/flow,samwgoldman/flow,samwgoldman/flow,facebook/flow,mroch/flow,gabelevi/flow,AgentME/flow,popham/flow,mroch/flow,AgentME/flow,jamesgpearce/flow,facebook/flow,facebook/flow,samwgoldman/flow,gabelevi/flow,popham/flow,mroch/flow,gabelevi/flow,facebook/flow,mroch/flow,jamesgpearce/flow,popham/flow,AgentME/flow,gabelevi/flow,samwgoldman/flow,facebook/flow,AgentME/flow,gabelevi/flow,samwgoldman/flow