[libc-commits] [libc] [libc] Support %lc in printf (PR #169983)

[Shubh Pachchigar via libc-commits]

shubhe25p wrote:

This PR has spun up three new interesting directions, each of which seems feasible with some guidance. I am not sure which one can be pulled into this PR and if it is even an issue. Let me know your thoughts @michaelrj-google:

1. `wchar` is a distinct integral type in C++ standard but `BigInt` guard clause will throw an error as `wchar` is not recognized. Here I have a workaround where I cast to `unsigned int`. So the work will involve adding `wchar` to `BigInt`.
2. `wchar` support on windows, currently a static assert in `wcrtomb` causes a build failure on windows platforms and work will involve adding UTF-16 support to wcrtomb
3. `%ls` support in printf, which is a natural extension to this work and would involve a looping over a sequence of `wchar`

https://github.com/llvm/llvm-project/pull/169983