External Items with Rust ABI need to mangle the full path

[philberty]

When compiling external rust abi item requires the fully qualified
canonical path to be mangled in order to link correctly.

[philberty]

bors r+

[bjorn3]

#[no_mangle] is what determines if symbol mangling should happen, not the calling convention. You should mangle all functions not marked as #[no_mangle] and mangle all imported functions unless they are imported using an extern "..." { ... } block.

[bors]

Build succeeded:

• build-and-check

[bjorn3]

@philberty