patch 8.2.0677: Vim9: no support for closures

Problem:    Vim9: no support for closures.
Solution:   Find variables in the outer function scope, so long as the scope
            exists.
diff --git a/src/userfunc.c b/src/userfunc.c
index 708b452..2493dfe 100644
--- a/src/userfunc.c
+++ b/src/userfunc.c
@@ -14,19 +14,6 @@
 #include "vim.h"
 
 #if defined(FEAT_EVAL) || defined(PROTO)
-// flags used in uf_flags
-#define FC_ABORT    0x01	// abort function on error
-#define FC_RANGE    0x02	// function accepts range
-#define FC_DICT	    0x04	// Dict function, uses "self"
-#define FC_CLOSURE  0x08	// closure, uses outer scope variables
-#define FC_DELETED  0x10	// :delfunction used while uf_refcount > 0
-#define FC_REMOVED  0x20	// function redefined while uf_refcount > 0
-#define FC_SANDBOX  0x40	// function defined in the sandbox
-#define FC_DEAD	    0x80	// function kept only for reference to dfunc
-#define FC_EXPORT   0x100	// "export def Func()"
-#define FC_NOARGS   0x200	// no a: variables in lambda
-#define FC_VIM9	    0x400	// defined in vim9 script file
-
 /*
  * All user-defined functions are found in this hashtable.
  */
@@ -3267,7 +3254,7 @@
 
     // ":def Func()" needs to be compiled
     if (eap->cmdidx == CMD_def)
-	compile_def_function(fp, FALSE);
+	compile_def_function(fp, FALSE, NULL);
 
     goto ret_free;