Bug 1183400 - Remove SyntacticContext::Delete, now addressed by modifying how delete nodes are folded. r=efaust

--HG--
extra : rebase_source : 65e34a4c142051c17d3e6cf1ae3111b0130a8f46

js/src/frontend/FoldConstants.cpp

@@ -512,9 +512,6 @@ enum class SyntacticContext : int {
     // or || in such a context.
     Condition,
 
-    // pn is the operand of the 'delete' keyword.
-    Delete,
-
     // Any other syntactic context.
     Other
 };