Move plugin processing to top of plugins (#6381)

* centralize plugin options

* Centralize plugins options

- move more options to the top
- move validations that depend on options to the top

* use isLoose option

* Move more validations to the top

* Move ref parameter for rewriteModuleStatementsAndPrepareHeader() to the top

* fix eslint errors

* remove unused parameter

* set default systemGlobal value

* Revert "Move ref parameter for rewriteModuleStatementsAndPrepareHeader() to the top"

This reverts commit b3855302d17fa19d8acb4c8accab3680c8d2710e.

* Revert "Move more validations to the top"

This reverts commit e5861d8a034ff8f553391f55654f753bcf428a5d.

* fix allowMutablePropsOnTags option usage

* improve naming

* change Contructor definition for sake of consistency

* move allowMutablePropsOnTags validation to the top

* add missing !

packages/babel-plugin-transform-es2015-classes/src/index.js

@@ -3,7 +3,10 @@ import VanillaTransformer from "./vanilla";
 import annotateAsPure from "babel-helper-annotate-as-pure";
 import nameFunction from "babel-helper-function-name";
 
-export default function({ types: t }) {
+export default function({ types: t }, options) {
+  const { loose } = options;
+  const Constructor = loose ? LooseTransformer : VanillaTransformer;
+
   // todo: investigate traversal requeueing
   const VISITED = Symbol();
 
@@ -50,9 +53,6 @@ export default function({ types: t }) {
 
         node[VISITED] = true;
 
-        let Constructor = VanillaTransformer;
-        if (state.opts.loose) Constructor = LooseTransformer;
-
         path.replaceWith(new Constructor(path, state.file).run());
 
         if (path.isCallExpression()) {