Problem:    Cannot have a comment halfway an expression in an autocmd command
            block.
Solution:   When skipping over the NL also skip over comments. (closes #10519)

Problem:    vim_regsub() can overwrite the destination.
Solution:   Pass the destination length, give an error when it doesn't fit.

Problem:    "textlock" is always zero.
Solution:   Remove "textlock" and rename "textwinlock" to "textlock".
            (closes #10489)

Problem:    Asan warns for undefined behavior.
Solution:   Cast the shifted value to unsigned.

Problem:    Right shift on negative number does not work as documented.
Solution:   Use a uvarnumber_T type cast.

Problem:    Cannot do bitwise shifts.
Solution:   Add the >> and << operators. (Yegappan Lakshmanan, closes #8457)

Problem:    Interpolated string expression requires escaping.
Solution:   Do not require escaping in the expression.

Problem:    Using execute() to define a lambda doesn't work. (Ernie Rael)
Solution:   Put the getline function in evalarg. (closes #10375)

Problem:    Comment inside an expression in lambda ignores the rest of the
            expression.
Solution:   Truncate the line at the comment. (closes #10367)

Problem:    Expression in command block does not look after NL when command is
            typed.
Solution:   Skip over NL also when not in a script. (closes #10358)