patch 8.1.1526: no numerical value for the patchlevel

Problem:    No numerical value for the patchlevel.
Solution:   Add v:versionlong.
diff --git a/src/vim.h b/src/vim.h
index 3b4582b..90208cd 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -1960,7 +1960,8 @@
 #define VV_TERMSTYLERESP 85
 #define VV_TERMBLINKRESP 86
 #define VV_EVENT	87
-#define VV_LEN		88	/* number of v: vars */
+#define VV_VERSIONLONG	88
+#define VV_LEN		89	// number of v: vars
 
 /* used for v_number in VAR_SPECIAL */
 #define VVAL_FALSE	0L