Fix space-unary-ops rule for keywords like `yield`. r=me (no bug) DONTBUILD

MozReview-Commit-ID: 8LHjOTKGis0

--HG--
extra : rebase_source : 672ff5d3b753a8e1240e009ce9eb972fdf05a0d1
extra : histedit_source : e5a0c34300e585091a9f64ce813c3cbe6b56147e

toolkit/components/extensions/.eslintrc

@@ -226,7 +226,7 @@
     "space-infix-ops": [2, {"int32Hint": true}],
 
     // ++ and -- should not need spacing
-    "space-unary-ops": [1, {"nonwords": false}],
+    "space-unary-ops": [1, {"nonwords": false, "words": true, "overrides": {"typeof": false}}],
 
     // No comparisons to NaN
     "use-isnan": 2,