[clang] [clang] Adding an API to create a `CXStringSet` from a Vector of `StringRef`s (PR #136773)

[Qiongsi Wu via cfe-commits]

qiongsiwu wrote:

> Where is this new API expected to be used?

An intended use can be found here https://github.com/swiftlang/llvm-project/pull/10524, where we try to pass up a collection of strings to the user, and we try not to create copies of the strings. 

https://github.com/llvm/llvm-project/pull/136773