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/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);