Fix for platforms not supporting atomic loads

[Oakchris1955]

The alloc::sync module is only available on platforms that support atomic loads and stores of pointers. This may be detected at compile time using #[cfg(target_has_atomic = ptr)].

I encountered this issue when a user of a project of mine detected that typed-path doesn't compile on thumbv6m-none-eabi targets.

P.S. Since this is essentially a patch fix and I'd like to be able to use this library on certain thumbv6m-none-eabi targets, is it possible to roll a patch version on crates.io? Thanks.

[chipsenkbeil]

@Oakchris1955 thanks! I merged this in and fixed some lint errors from the latest stable Rust.

I ended up publishing as 0.12.0 instead of 0.11.1 as there was a refactoring of a return type that also hadn't been captured in a new release. Did you need this to be backported into 0.11 as a patch?

[Oakchris1955]

Did you need this to be backported into 0.11 as a patch?

My crate uses v0.10 so I'd have to upgrade to a minor version even if this was released as a patch