patch 7.4.2106
Problem:    Clang warns about missing field in initializer.
Solution:   Define COMMA and use it.  (Kazunobu Kuriyama)
diff --git a/src/vim.h b/src/vim.h
index e2d4cc4..498078a 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -1765,6 +1765,7 @@
 # ifndef INIT
 #  define INIT(x) x
 #  define DO_INIT
+#  define COMMA ,
 # endif
 #endif