Bug 1194838 - Make Cell a GCType for the hazard analysis, r=terrence

--HG--
extra : rebase_source : ee7e5d60e650fcfda002228c5792362076170952

js/src/devtools/rootAnalysis/annotations.js

@@ -346,6 +346,7 @@ function isOverridableField(initialCSU, csu, field)
 
 function listGCTypes() {
     return [
+        'js::gc::Cell',
         'JSObject',
         'JSString',
         'JSFatInlineString',