[RFC] Time to deprecate & remove clang-rename?

The clang-rename project has existed in tree since about 2014, but its functionality has largely been superseded by clangd and this project hasn’t received much attention in many years. Further, our documentation on it still claims it’s in very early stages of development despite being ~10 years old. One of the primary people driving the tool has mentioned that they don’t believe there is a reason to continue to support it unless it’s still being actively used (⚙ D148439 [clang-rename] Exit gracefully when no input provided).

Should we deprecate and remove clang-rename, or are there folks still using this functionality? I don’t feel strongly that we need to remove the tool, but if we don’t have a need for the tool, we should probably remove it rather than let it bit-rot further. This would (very slightly) reduce maintenance burden, build times, repo clone times, etc. That said, if the tool is being used, we can continue to support it.