Rollup merge of #47535 - Manishearth:ignore-target, r=kennytm
Rollup merge of #47535 - Manishearth:ignore-target, r=kennytm

add target/ to ignored tidy dirs

Sometimes you get a target directory from running cargo in the rust repo (the root is `src/`), and it contains generated files. Just whitelist it since it causes tidy to spew warnings uncontrollably.

graydon/rust,GBGamer/rust,aidancully/rust,graydon/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,graydon/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,graydon/rust,graydon/rust,GBGamer/rust,aidancully/rust,aidancully/rust,graydon/rust,GBGamer/rust,aidancully/rust