License of ConvertUTF.cpp and ConvertUTF.h

[bkmgit]

The files ConvertUTF.h and ConvertUTF.cpp seem to be under non free licenses. The LLVM project has updated them, see here, with ConvertUTF.h from breakpad and ConvertUTF.cc also from breakpad. As indicated at AmokHuginnsson/replxx#12, they can also be replaced by https://github.com/nemtrif/utfcpp

[lemire]

These files are not part of the simdutf library. They are part of a benchmark routine which relies on other libraries. We state:

We include a few competitive solutions under the benchmarks/competition directory. 
They are provided for research purposes only.

The link you offer states that...

The code does not need to be replaced for license reasons. The files were
relicensed to a proper license by Unicode.org some 15 years ago, so we
fixed this issue for llvm by applying the "new" license terms to our copy.

We would, of course, invite the addition of utfcpp to our benchmarks. Pull request invited.