[llvm] [Runtimes] Merge 'compile_commands.json' files from runtimes build (PR #116303)

[Joseph Huber via llvm-commits]

jhuber6 wrote:

I fixed the issue where it would error if you manually deleted the dependency. Right now this properly re-merges it whenever the runtime compile commands changes. I believe this is very useful for making runtimes builds less painful, so hopefully there aren't any additional issues.

https://github.com/llvm/llvm-project/pull/116303