patch 8.2.1047: Vim9: script cannot use line continuation like :def function

Problem:    Vim9: script cannot use line continuation like in a :def function.
Solution:   Pass the getline function pointer to the eval() functions.  Use it
            for addition and multiplication operators.
diff --git a/src/proto/eval.pro b/src/proto/eval.pro
index 57dd838..4fb04eb 100644
--- a/src/proto/eval.pro
+++ b/src/proto/eval.pro
@@ -26,8 +26,8 @@
 void free_for_info(void *fi_void);
 void set_context_for_expression(expand_T *xp, char_u *arg, cmdidx_T cmdidx);
 int pattern_match(char_u *pat, char_u *text, int ic);
-int eval0(char_u *arg, typval_T *rettv, char_u **nextcmd, int flags);
-int eval1(char_u **arg, typval_T *rettv, int flags);
+int eval0(char_u *arg, typval_T *rettv, char_u **nextcmd, evalarg_T *evalarg);
+int eval1(char_u **arg, typval_T *rettv, evalarg_T *evalarg_in);
 void eval_addblob(typval_T *tv1, typval_T *tv2);
 int eval_addlist(typval_T *tv1, typval_T *tv2);
 char_u *partial_name(partial_T *pt);
diff --git a/src/proto/scriptfile.pro b/src/proto/scriptfile.pro
index e2a2671..b5b8aae 100644
--- a/src/proto/scriptfile.pro
+++ b/src/proto/scriptfile.pro
@@ -22,6 +22,7 @@
 linenr_T *source_breakpoint(void *cookie);
 int *source_dbg_tick(void *cookie);
 int source_level(void *cookie);
+char_u *source_nextline(void *cookie);
 int do_source(char_u *fname, int check_other, int is_vimrc, int *ret_sid);
 void ex_scriptnames(exarg_T *eap);
 void scriptnames_slash_adjust(void);