UNION bug

[jievince]

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Describe the bug (required)
The following sentence reports a syntax error.

    UNWIND [1,2] AS a RETURN a
    UNION ALL
    RETURN 2 AS a

While the following could executed successfully:

      UNWIND [1,2] AS a RETURN a
      UNION ALL
      UNWIND [2] AS a RETURN a

Your Environments (required)

• OS: uname -a
• Compiler: g++ --version or clang++ --version
• CPU: lscpu
• Commit id (e.g. a3ffc7d8)

How To Reproduce(required)

Steps to reproduce the behavior:

1. Step 1
2. Step 2
3. Step 3

Expected behavior

Additional context