servo: Merge #4791 - Add /.servo .gitignore to ignore the local compiler binary cache (from saneyuki:ignore); r=jdm

follow up #4755

Source-Repo: https://github.com/servo/servo
Source-Revision: 816a3c2d916625b1e4863da6c55167c83b58c2e1

servo/.gitignore

@@ -12,6 +12,7 @@
 /components/script/dom/bindings/codegen/Bindings
 /components/script/dom/bindings/codegen/test/*.rs
 /.servobuild
+/.servo
 /tests/wpt/_virtualenv
 *~
 *#