move all plugin tests out of babel-core and into their appropriate folders

packages/babel-plugin-transform-jscript/test/fixtures/jscript/var-named-function-expression/actual.js

@@ -0,0 +1,7 @@
+var IdenticalName = function IdenticalName(x) {
+  return x;
+};
+
+(function foo() {
+
+});

packages/babel-plugin-transform-jscript/test/fixtures/jscript/var-named-function-expression/expected.js

@@ -0,0 +1,13 @@
+var IdenticalName = (function () {
+  function IdenticalName(x) {
+    return x;
+  }
+
+  return IdenticalName;
+})();
+
+(function () {
+  function foo() {}
+
+  return foo;
+})();