The self program compiles the compiler source of the checkout the programs
come from (the baseline by default), so a change adding compiler code the
self-hosted frontend cannot lower passed the gate and failed CI's
self-hosting tests. With the self set, the gate now also builds the
candidate's packages/compiler/src/native/cli.ts with the candidate (LLVM
only, not compared) and fails when that build fails.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>