Auto merge of rust-lang#102167 - thomcc:exclusive-inline, r=scottmcm

Add `#[inline]` to trivial functions on `core::sync::Exclusive`

When optimizing for size things like these sometimes don't inlined even though they're generic. This is bad because they're no-ops.

Only dodgy one is poll I guess since it forwards to the inner poll, but it's not like we're doing `#[inline(always)]` here.

Author: bors