x11-wm/leftwm: fix build on powerpc

error[E0432]: unresolved imports `core::sync::atomic::AtomicI64`, `core::sync::atomic::AtomicU64`
  --> /wrkdirs/usr/ports/x11-wm/leftwm/work/leftwm-0.2.9/cargo-crates/crossbeam-utils-0.8.5/src/lib.rs:79:49
   |
79 |             pub(crate) use core::sync::atomic::{AtomicI64, AtomicU64};
   |                                                 ^^^^^^^^^  ^^^^^^^^^ no `AtomicU64` in `sync::atomic`
   |                                                 |
   |                                                 no `AtomicI64` in `sync::atomic`
   |
help: a similar name exists in the module
   |
79 |             pub(crate) use core::sync::atomic::{AtomicI8, AtomicU64};
   |                                                 ~~~~~~~~
help: a similar name exists in the module
   |
79 |             pub(crate) use core::sync::atomic::{AtomicI64, AtomicU8};
   |                                                            ~~~~~~~~

error[E0412]: cannot find type `AtomicU64` in module `core::sync::atomic`
    --> /wrkdirs/usr/ports/x11-wm/leftwm/work/leftwm-0.2.9/cargo-crates/crossbeam-utils-0.8.5/src/atomic/consume.rs:78:14
     |
78   |   impl_atomic!(AtomicU64, u64);
     |                ^^^^^^^^^ help: a struct with a similar name exists: `AtomicU16`

error[E0412]: cannot find type `AtomicI64` in module `core::sync::atomic`
    --> /wrkdirs/usr/ports/x11-wm/leftwm/work/leftwm-0.2.9/cargo-crates/crossbeam-utils-0.8.5/src/atomic/consume.rs:80:14
     |
80   |   impl_atomic!(AtomicI64, i64);
     |                ^^^^^^^^^ help: a struct with a similar name exists: `AtomicI16`

Some errors have detailed explanations: E0412, E0432.
For more information about an error, try `rustc --explain E0412`.
error: could not compile `crossbeam-utils` due to 3 previous errors