Fix compilation with --solo and --debug combined.

madler · madler · commit e13def040e12 · 2017-01-02T18:21:29.000-08:00
However this ends up not really being solo, since it has to
include external libraries.
diff --git a/zutil.c b/zutil.c
@@ -113,7 +113,7 @@ uLong ZEXPORT zlibCompileFlags()
 }
 
 #ifdef ZLIB_DEBUG
-
+#include <stdlib.h>
 #  ifndef verbose
 #    define verbose 0
 #  endif

Original file line number	Diff line number	Diff line change
`@@ -113,7 +113,7 @@ uLong ZEXPORT zlibCompileFlags()`
`113`	`113`	`}`
`114`	`114`
`115`	`115`	`#ifdef ZLIB_DEBUG`
`116`		`-`
	`116`	`+#include <stdlib.h>`
`117`	`117`	`# ifndef verbose`
`118`	`118`	`# define verbose 0`
`119`	`119`	`# endif`