Removed the deprecated jsx pragma detection code (#6145)

* Removed the deprecated jsx pragma detection code and the concerned tests that included jsx-pragma

* Removed extra tests

* Restored packages/babel-plugin-transform-react-jsx/test/fixtures/react/honor-custom-jsx-pragma-option/

packages/babel-plugin-transform-react-jsx/src/index.js

@@ -2,8 +2,6 @@ import jsx from "babel-plugin-syntax-jsx";
 import helper from "babel-helper-builder-react-jsx";
 
 export default function({ types: t }) {
-  const JSX_ANNOTATION_REGEX = /\*?\s*@jsx\s+([^\s]+)/;
-
   const visitor = helper({
     pre(state) {
       const tagName = state.tagName;
@@ -21,23 +19,7 @@ export default function({ types: t }) {
   });
 
   visitor.Program = function(path, state) {
-    const { file } = state;
-    let id = state.opts.pragma || "React.createElement";
-
-    for (const comment of (file.ast.comments: Array<Object>)) {
-      const matches = JSX_ANNOTATION_REGEX.exec(comment.value);
-      if (matches) {
-        id = matches[1];
-        if (id === "React.DOM") {
-          throw file.buildCodeFrameError(
-            comment,
-            "The @jsx React.DOM pragma has been deprecated as of React 0.12",
-          );
-        } else {
-          break;
-        }
-      }
-    }
+    const id = state.opts.pragma || "React.createElement";
 
     state.set("jsxIdentifier", () =>
       id