Parser fails on comments without preceding code

[radeusgd]

General Summary

Parsing error is encountered with comments that don't have any code preceding them on the same line.

Steps to Reproduce

1. Create a file TstComment.luna with following content

def main:
    # Test
    print "a"
    0

2. Execute luna run --target TstComment.luna

Expected Result

Program should print "a" and finish cleanly.

Actual Result

The program fails to run with the following error:

Running in interpreted mode.
Exception "Unexpected (report this as a bug): UniTermDocumented (Documented (SmallVector (Struct (Ptr 0x00007f440065dfc4))) (Component 0x00007f443c19b8b0))"

Luna Version

luna (linux-x86_64) (ghc-8.4) [master@1f5f7194f371ea17df3c2f56f1c85a8eb6f3a320, Clean, 967 commits, latest on Mon Dec 10 09:33:03 2018 +0100]