patch 8.2.2378: Vim9: no error message for dividing by zero

Problem:    Vim9: no error message for dividing by zero.
Solution:   Give an error message. (issue #7704)
diff --git a/src/eval.c b/src/eval.c
index 13ee49a..40c6feb 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -63,8 +63,10 @@
 {
     varnumber_T	result;
 
-    if (n2 == 0)	// give an error message?
+    if (n2 == 0)
     {
+	if (in_vim9script())
+	    emsg(_(e_divide_by_zero));
 	if (n1 == 0)
 	    result = VARNUM_MIN; // similar to NaN
 	else if (n1 < 0)
@@ -84,7 +86,8 @@
 	varnumber_T
 num_modulus(varnumber_T n1, varnumber_T n2)
 {
-    // Give an error when n2 is 0?
+    if (n2 == 0 && in_vim9script())
+	emsg(_(e_divide_by_zero));
     return (n2 == 0) ? 0 : (n1 % n2);
 }