vim-patch:8.2.1161: Vim9: using freed memory

Problem:    Vim9: using freed memory.
Solution:   Put pointer back in evalarg instead of freeing it.

8e2730a315

Omit eval_tofree_lambda: Vim9 script only.

N/A patches for version.c:

vim-patch:8.2.1163: build error

Problem:    Build error.
Solution:   Add missing change to globals.

6e13530ca0

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

src/nvim/eval.h

@@ -275,7 +275,7 @@ typedef struct {
   LineGetter eval_getline;
   void *eval_cookie;  ///< argument for eval_getline()
 
-  /// pointer to the line obtained with getsourceline()
+  /// pointer to the last line obtained with getsourceline()
   char *eval_tofree;
 } evalarg_T;