macro export shadowing/duplicate

[Mark-Simulacrum]

• root: adhesion-0.5.0: start v. end
• root: chylli/rust-busybox: start v. end

root: fixed-hash - 4 (4 gh, 0 crates.io) detected crates which regressed due to this

• CodeChain-io/codechain-blake-miner: start v. end
• CodeChain-io/codechain-cuckoo-miner: start v. end
• NervosFoundation/serde_bench: start v. end
• TheWaWaR/cita-create-genesis: start v. end

root: lsio - 2 (0 gh, 2 crates.io) detected crates which regressed due to this

• lsio-0.1.18: start v. end
• opentracing-0.1.0: start v. end

cc @petrochenkov

cc #49084 (though not directly relevant)

I suspect this is a semi-intentional change.

These crates also fail, but with shadowing of built-ins; I suspect this is the same bug:

• root: conniecs-0.2.0: start v. end

• root: lightning-wire-msgs-0.2.1: start v. end

root: lime-render - 2 (1 gh, 1 crates.io) detected crates which regressed due to this

• lime-0.1.0: start v. end
• andrewhickman/ecs-demo: start v. end

[Centril]

Intentionally made an error in 8e27c4f.