Auto merge of #100782 - thomcc:fix-android-sigaddset, r=Mark-Simulacrum

Auto merge of #100782 - thomcc:fix-android-sigaddset, r=Mark-Simulacrum

Align android `sigaddset` impl with the reference impl from Bionic

In https://github.com/rust-lang/rust/pull/100737 I noticed we were treating the sigset_t as an array of bytes, while referencing code from android (https://github.com/aosp-mirror/platform_bionic/blob/ad8dcd6023294b646e5a8288c0ed431b0845da49/libc/include/android/legacy_signal_inlines.h) which treats it as an array of unsigned long.

That said, the behavior difference is so subtle here that it's not hard to see why nobody noticed. This fixes the implementation to be equivalent to the one in bionic.