[LifetimeAnalysis] Support std::stack::top() and std::optional::value()

Summary: Diagnose dangling pointers that come from std::stack::top() and std::optional::value().

Reviewers: gribozavr

Subscribers: cfe-commits, xazax.hun

Tags: #clang

Differential Revision: https://reviews.llvm.org/D66164

llvm-svn: 368929