Auto merge of #7208 - ehuss:fix-old-build-script-test, r=alexcrichton
Auto merge of #7208 - ehuss:fix-old-build-script-test, r=alexcrichton

Fix an old test.

This test was added in f888b4b7802d4c4699490af3810ce7dadf387915, part of #792, in a commented state. Might as well make it work. It is a bit surprising that passing `-l nonexistinglib` doesn't cause an error, but seems to be fine.

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