patch 7.4.1216
Problem:    Still using HAVE_STDARG_H.
Solution:   Assume it's always defined.
diff --git a/src/vim.h b/src/vim.h
index 1cab32d..18610f5 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -508,9 +508,7 @@
 #ifdef HAVE_WCTYPE_H
 # include <wctype.h>
 #endif
-#ifdef HAVE_STDARG_H
-# include <stdarg.h>
-#endif
+#include <stdarg.h>
 
 #if defined(HAVE_SYS_SELECT_H) && \
 	(!defined(HAVE_SYS_TIME_H) || defined(SYS_SELECT_WITH_SYS_TIME))