Fix type-inference regression in #112225
The type inference of argument-position closures and async blocks regressed in 1.70 as the evaluation order of async blocks changed, as they are not implicitly wrapped in an identity-function anymore.
Fixes#112225 by making sure the evaluation order stays the same as it used to.
r? `@compiler-errors`
As this was a stable-to-stable regression, it might be worth to consider backporting. Although the workaround for this is trivial as well: Just wrap the async block in another block.
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