snapshot_20241222

Add an option to allow "clangd.path" to point to a shell script

In VSCode 1.92 and later (which uses node 20), this requires passing `shell: true` in the executable options.

However, using `shell: true` changes the behavior in some other ways, e.g. the path and arguments now have to be quoted in case they contain spaces.

To avoid the potential for regressions from using `shell: true`, its use is made conditional on a new clangd option, "clangd.useScriptAsExecutable".

Fixes #683