move minification.deadCodeElimination back to the builtin-setup transformer group

src/babel/transformation/transformers/index.js

@@ -8,13 +8,13 @@ export default {
   "minification.removeConsole":            require("./minification/remove-console"),
   "utility.inlineEnvironmentVariables":    require("./utility/inline-environment-variables"),
   "minification.constantFolding":          require("./minification/constant-folding"),
+  "minification.deadCodeElimination":      require("./minification/dead-code-elimination"),
   _modules:                                require("./internal/modules"),
   "spec.functionName":                     require("./spec/function-name"),
 
   //- builtin-basic
   // this is where the bulk of the ES6 transformations take place, none of them require traversal state
   // so they can all be concatenated together for performance
-  "minification.deadCodeElimination":      require("./minification/dead-code-elimination"),
   "es7.classProperties":                   require("./es7/class-properties"),
   "es7.trailingFunctionCommas":            require("./es7/trailing-function-commas"),
   "es7.asyncFunctions":                    require("./es7/async-functions"),

src/babel/transformation/transformers/minification/dead-code-elimination.js

@@ -19,7 +19,7 @@ function toStatements(node) {
 
 export var metadata = {
   optional: true,
-  group: "builtin-basic"
+  group: "builtin-setup"
 };
 
 export function ReferencedIdentifier(node, parent, scope) {