C++: Model more stringstream features#4253

Merged

jbj merged 8 commits intogithub:mainfrom

geoffw0:stringstream2

Sep 15, 2020

Commits on Sep 9, 2020

C++: Model std::stringstream::str.
geoffw0
committed

Commits on Sep 14, 2020

C++: Repair taint flow from previous.
geoffw0
committed