Move to C++14
Summary:
I just bumped the minimum compiler versions to support C++14 in D66188.
Following our process and our previous agreement, I'm now officially bumping the C++ version to 14 and updating the documentation.
Subscribers: mgorny, jkorous, dexonsmith, llvm-commits, chandlerc, thakis, EricWF, jyknight, lhames, JDevlieghere
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66195
llvm-svn: 368887