Auto merge of #8469 - ehuss:long-filename-windows, r=alexcrichton
Auto merge of #8469 - ehuss:long-filename-windows, r=alexcrichton

Disable long_file_names test if not supported on Windows.

This test will fail on Windows if Cargo's target directory is over 80 characters long (as it is in rust's CI).

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