feature pooling-allocator doesn't compile on its own

[FrankReh]

Trying to get parts of wasmtime to compile without enlisting all features.

The pooling-allocator feature pulls in some code but uses a field that is only defined when the crate/wasmtime feature "async" is defined.

wasmtime $ cargo check --no-default-features --features pooling-allocator
error[E0599]: no method named `total_stacks` found for struct `PoolingAllocationConfig` in the current scope
   --> crates/cli-flags/src/lib.rs:593:29
    |
593 |                         cfg.total_stacks(limit);
    |                             ^^^^^^^^^^^^
    |

[fitzgen]

Thanks for the bug report -- fix over in https://github.com/bytecodealliance/wasmtime/pull/8891

[FrankReh]

Thanks @fitzgen!