Feature request: view flambda/cmm/lambda/assembly

When working on performance sensitive native code, I'm regularly diving into the flambda/cmm/lambda/assembly code to get a better understanding of what the code actually does. It would be very handy if I could query that information through the language server.

No files, tests, or entry points are named. Start by locating the language-server request handling and the compiler integration for flambda, cmm, lambda, and assembly output; done means users can query that information through the language server.

Written by the indexing model from the issue text.