patch 8.2.1297: when a test fails it's often not easy to see where

Problem:    When a test fails it's often not easy to see what the call stack
            is.
Solution:   Add more entries from the call stack in the exception message.
diff --git a/src/debugger.c b/src/debugger.c
index 91ab5ee..00fb9c8 100644
--- a/src/debugger.c
+++ b/src/debugger.c
@@ -105,7 +105,7 @@
 	vim_free(debug_newval);
 	debug_newval = NULL;
     }
-    sname = estack_sfile();
+    sname = estack_sfile(FALSE);
     if (sname != NULL)
 	msg((char *)sname);
     vim_free(sname);
@@ -344,7 +344,7 @@
     }
     else
     {
-	char_u	*sname = estack_sfile();
+	char_u	*sname = estack_sfile(FALSE);
 	int	max = get_maxbacktrace_level(sname);
 
 	if (debug_backtrace_level > max)
@@ -365,7 +365,7 @@
     int	    i = 0;
     int	    max;
 
-    sname = estack_sfile();
+    sname = estack_sfile(FALSE);
     max = get_maxbacktrace_level(sname);
     if (sname != NULL)
     {