[clang] [clang-tools-extra] Remove `StringLiteral` in favor of `StringRef` (PR #122366)

[Sergei Barannikov via cfe-commits]

s-barannikov wrote:

> * the `strlen` is NOT constant-evaluated on MSVC, even the latest version.

The godbolt link shows otherwise?

https://github.com/llvm/llvm-project/pull/122366