Codegen: cond ? await a() : b() evaluates BOTH ternary branches

[proggeramlug]

What happened

When a conditional expression has await on one branch and a synchronous call on the other, Perry's codegen evaluates both branches at runtime, regardless of the condition.

What you expected

Only the branch matching the condition should be evaluated, matching JS/TS semantics.

Minimal reproduction

async function a(): Promise<number> { console.log('ran a'); return 1; }
function       b():        number    { console.log('ran b'); return 2; }

async function main(): Promise<void> {
  const cmd: string = 'digest';
  const r = cmd === 'fetch' ? await a() : b();
  console.log('r=' + r);
  process.exit(0);
}
main().catch((e) => { console.log(e); process.exit(1); });

Command:

perry compile repro.ts -o repro
./repro

Observed output:

ran a
ran b
r=2

Expected output (matches Node):

ran b
r=2

(Only b should run; cmd === 'fetch' is false.)

A purely-sync ternary cond ? a() : b() works correctly — only one branch runs. The bug is specific to await appearing on one side.

Workaround that works:

let r: number;
if (cmd === 'fetch') {
  r = await a();
} else {
  r = b();
}

Environment

• Perry version: 0.5.395
• Host OS: macOS 26.4 (arm64)
• Target: native
• Installed via: cargo (~/.cargo/bin/perry)

Diagnostic output

No errors or warnings.

Found while compiling skelpo-listener: dispatching args.command === 'fetch' ? await runFetch(args) : runDigest(args) — under Perry, runFetch ran during a digest invocation, contaminating the digest output with fetch progress.