patch 9.1.0984: exception handling can be improved

Problem:  exception handling can be improved
Solution: add v:stacktrace and getstacktrace()

closes: #16360

Co-authored-by: Naruhiko Nishino <naru123456789@gmail.com>
Signed-off-by: ichizok <gclient.gaap@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/evalfunc.c b/src/evalfunc.c
index ec108b0c..d81480b 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -2170,6 +2170,8 @@
 			ret_string,	    f_getregtype},
     {"getscriptinfo",	0, 1, 0,	    arg1_dict_any,
 			ret_list_dict_any,  f_getscriptinfo},
+    {"getstacktrace",	0, 0, 0,	    NULL,
+			ret_list_dict_any,  f_getstacktrace},
     {"gettabinfo",	0, 1, FEARG_1,	    arg1_number,
 			ret_list_dict_any,  f_gettabinfo},
     {"gettabvar",	2, 3, FEARG_1,	    arg3_number_string_any,