Top-level await code: exec() silently discards it, use eval()

Code compiled with compile(src, name, 'exec', flags=ast.PyCF_ALLOW_TOP_LEVEL_AWAIT) that contains a top-level await/async for/async with becomes a coroutine when evaluated. eval(code, ns) returns that coroutine (run it with asyncio.run; assignments land in ns). exec(code, ns) returns None and drops it: none of the block runs, not even statements before the first await, and the only trace is 'RuntimeWarning: coroutine <module> was never awaited'. A block without await compiles fine under the flag, runs immediately, and eval returns None, so check asyncio.iscoroutine(result) before asyncio.run. Verified identical on CPython 3.9 through 3.15.