build-sys: Include <stdlib.h> in ./configure wchar_t test

Without #include <stdlib.h>, this configure check fails for strict
C99/C11 compilers which do not support implicit function declarations
(which are a C90 feature removed from C99).

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/configure.ac b/configure.ac
index a840e20ee8be24b5d3da70560eddf52722620d64..997b6388cb0538b06163d94ad0fac70b47e406ce 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -756,6 +756,7 @@ UL_REQUIRES_COMPILE([widechar], [[
   #include <wchar.h>
   #include <wctype.h>
   #include <stdio.h>
+  #include <stdlib.h>
   ]], [[
     wchar_t wc;
     wint_t w;