patch 7.4.1976
Problem:    Number variables are not 64 bits while they could be.
Solution:   Add the num64 feature. (Ken Takata)
diff --git a/src/misc2.c b/src/misc2.c
index 2dd89f9..4ed715b 100644
--- a/src/misc2.c
+++ b/src/misc2.c
@@ -2719,7 +2719,7 @@
     int		modifiers;
     int		bit;
     int		key;
-    unsigned long n;
+    uvarnumber_T	n;
     int		l;
 
     src = *srcp;