Bug: throw Unexpected Name when pass string literal

- `babel-plugin-preval` version: 5.0.0 (preval.macro 3.0.0)
- `node` version: v14.16.1
- `npm` (or `yarn`) version: 6.14.12

Relevant code or config

```javascript
export const searchPosts = preval`
const tool = require('../../graphql/utils');
module.exports = tool.maxDepth("searchPosts", 2);
`
```

What happened:
The `"searchPosts"` supposed to be a string literal, but this is what happened
```
preval.macro: Syntax Error: Unexpected Name "searchPosts". Learn more: https://www.npmjs.com/package/preval.macro
```

Reproduction repository:
I'll provide it when needed

Start with the preval tagged-template example and reproduce it with the listed babel-plugin-preval, preval.macro, Node, and npm versions. Check how the string literal passed to ../../graphql/utils is parsed; done means the example no longer reports Unexpected Name "searchPosts".

Written by the indexing model from the issue text.