vim-patch:8.2.1074: Vim9: no line break allowed after some operators

Problem:    Vim9: no line break allowed after some operators.
Solution:   Skip a line break after the operator.  Add
            eval_may_get_next_line() to simplify checking for a line break.

9215f01218

Co-authored-by: Bram Moolenaar <Bram@vim.org>

src/nvim/eval.c

@@ -3023,7 +3023,6 @@ static int eval7(char **arg, typval_T *rettv, evalarg_T *const evalarg, bool wan
     *arg = skipwhite(*arg + 1);
 
     ret = eval1(arg, rettv, evalarg);  // recursive!
-
     if (**arg == ')') {
       (*arg)++;
     } else if (ret == OK) {