Initial host buildscripts

These scripts allow the rust toolchain manifest to build the next host
rustc using the current prebuilt.

Bug: 129701460
Change-Id: I8078e1704957de9d8b18d802c6238d543374aa56
3 files changed
tree: 8fa4b2e83ebf8f7071a41804132a29409030263c
  1. build.py
  2. config_toml.py
  3. paths.py