Prove and implement the CIRCT lowering boundary

Amp-Thread-ID: https://ampcode.com/threads/T-019f876e-f033-7148-bb2d-08e0ed053ce3
Co-authored-by: Amp <amp@ampcode.com>
1615ef042fBattery Bot committed on 7/22/2026, 6:45:40 AMparentf48124d
10 files changed+1003-0