Rollup merge of #138179 - cuviper:x, r=jieyouxu

Add `src/tools/x` to the main workspace

The original reason to exclude it was so it could run before submodules
were initialized. However, those have all been converted to subtrees
now, so the entire workspace is always ready to go.

I've also alphabetized the workspace members, as it was an untidy mess. 🧹

Author: jhpratt