Incorrect comparison of source positions

[kfcripps]

The == operator of the SourcePosition class (lib/source_file.h:65) is implemented incorrectly.
It should be

return columnNumber == rhs.columnNumber &&
                lineNumber == rhs.lineNumber;

or

return lineNumber == rhs.lineNumber &&
                columnNumber == rhs.columnNumber;

instead of

return columnNumber == rhs.columnNumber &&
                lineNumber == rhs.columnNumber;

[mihaibudiu]

Fixed by #2388