various programs with unmatching curlies and parens do not cause SyntaxError to be thrown

```
> require('syntax-error')('})({')
undefined
```

Start by reproducing the reported require('syntax-error')('})({') case through the package entry point and inspect how unmatched curly braces and parentheses are parsed. Verify that the malformed input produces a SyntaxError, then add coverage for the reported case and other mismatched delimiters if the existing tests expose them.

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