CVE-2020-35906: futures_task::waker may cause a use-after-free if used on a type that isn't 'static

The vulnerability stems from the waker function's missing 'static bound on its generic type parameter. Multiple sources confirm this: 1) The RustSec advisory explicitly lists futures_task::waker as the affected function. 2) The GitHub PR #2206 shows the fix adding the 'static bound to the function signature. 3) The CVE description demonstrates how non-'static data leads to use-after-free through this function. The function's role in creating wakers from potentially short-lived data makes it the clear entry point for the vulnerability.