patch 8.2.1323: Vim9: invalid operators only rejected in :def function

Problem:    Vim9: invalid operators only rejected in :def function.
Solution:   Also reject them at script level. (closes #6564)
diff --git a/src/vim9compile.c b/src/vim9compile.c
index f150904..cf08e95 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -3633,7 +3633,7 @@
     }
 }
 
-    static exptype_T
+    exptype_T
 get_compare_type(char_u *p, int *len, int *type_is)
 {
     exptype_T	type = EXPR_UNKNOWN;