Introduce a standalone tool to remap paths inside clangd background
index files. This allows users to pay the cost of generating a full
background index once, then reuse the background index across multiple
clients. Each client rewrites the background index in place after
copying the original, specifying the path(s) to be remapped.
This is an alternative approach to the dynamic path remapping proposed
in #180285.
Fixesclangd/clangd#847
Assisted-by: claude
c1ea10a854