Due to https://github.com/rust-lang/rust/issues/62558, the tools: rls,
clippy, and rustfmt cannot be built.
We also remove src which cuts the resulting size of the dep from about
330MB to 180MB.
The build is further broken into two steps:
1. `x.py dist`
2. `x.py install`
This change is because `x.py install` now fails due to an issue where
bootstrap tries to install rustc-aarch64-linux-android before the
installation script is generated.
