Avoid node duplication to fix spread bug with import. (#6657)

packages/babel-plugin-transform-spread/test/fixtures/regression/6647/actual.js

@@ -0,0 +1,2 @@
+import a from 'a';
+a.preview(...c);

packages/babel-plugin-transform-spread/test/fixtures/regression/6647/expected.js

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+"use strict";
+
+var _a = babelHelpers.interopRequireDefault(require("a"));
+
+_a.default.preview.apply(_a.default, babelHelpers.toConsumableArray(c));

packages/babel-plugin-transform-spread/test/fixtures/regression/6647/options.json

@@ -0,0 +1,3 @@
+{
+  "plugins": ["external-helpers", "transform-spread", "transform-modules-commonjs"]
+}