Replace some const std::string & with llvm::StringRef or std::string

and std::move to avoid implicit std::string construction.

Part 1/2.

Patch by Eugene Kosov.




git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@241319 91177308-0d34-0410-b5e6-96231b3b80d8