Custom output path for compile_commands.json

[ikar49]

Hello! Thank you for your project!

How about the possibility to set a custom path for the generated compile-commands.json? Clangd supports this with the --compile-commands-dir parameter.

Motivation:

1. We mount source directory by network sometime and want not to create a big files in this (size of our compile_commands.json around 5 Gib).
2. We have a lot of projects in our monorepository and some of them use the root of monorepo as workspace root. Thus, compile_commands.json of these projects override each other.