updated for version 7.4.188

Problem:    SIZEOF_LONG clashes with similar defines in header files.
Solution:   Rename to a name starting with VIM_.  Also for SIZEOF_INT.

src/spell.c

@@ -317,7 +317,7 @@
 
 /* Type used for indexes in the word tree need to be at least 4 bytes.  If int
  * is 8 bytes we could use something smaller, but what? */
-#if SIZEOF_INT > 3
+#if VIM_SIZEOF_INT > 3
 typedef int idx_T;
 #else
 typedef long idx_T;