Auto merge of #7888 - ehuss:fingerprint-debug, r=Eh2406
Auto merge of #7888 - ehuss:fingerprint-debug, r=Eh2406

Add some extra fingerprint debug information.

There have been some situations where the existing log info was not sufficient to understand the cause of a rebuild.  I hope that this additional information can help with debugging problems.

vojtechkral/cargo,nipunn1313/cargo,tshepang/cargo,rust-lang/cargo,rustyhorde/cargo,tshepang/cargo,eminence/cargo,eminence/cargo,tsurai/cargo,vojtechkral/cargo,nipunn1313/cargo,tsurai/cargo,tsurai/cargo,nipunn1313/cargo,vojtechkral/cargo,rustyhorde/cargo,tsurai/cargo,rust-lang/cargo,rust-lang/cargo,nipunn1313/cargo,eminence/cargo,rustyhorde/cargo,tshepang/cargo,tsurai/cargo,rust-lang/cargo,rustyhorde/cargo,tshepang/cargo,vojtechkral/cargo,eminence/cargo