kakasi: avoid an implicit declaration of exit.

This caused the following false alarm:

```
error: can not use EUC-JP or UTF-8 encoding on iconv
```

See https://git.launchpad.net/ubuntu/+source/kakasi/commit/?h=applied/ubuntu/plucky&id=08f53a5.

pkgs/by-name/ka/kakasi/package.nix

@@ -2,6 +2,8 @@
   lib,
   stdenv,
   fetchurl,
+  fetchpatch,
+  autoreconfHook,
   libiconv,
 }:
 
@@ -9,6 +11,7 @@ stdenv.mkDerivation rec {
   pname = "kakasi";
   version = "2.3.6";
 
+  nativeBuildInputs = [ autoreconfHook ];
   buildInputs = lib.optionals stdenv.hostPlatform.isDarwin [ libiconv ];
 
   meta = with lib; {
@@ -28,6 +31,13 @@ stdenv.mkDerivation rec {
     sha256 = "1qry3xqb83pjgxp3my8b1sy77z4f0893h73ldrvdaky70cdppr9f";
   };
 
+  patches = [
+    (fetchpatch {
+      url = "https://src.fedoraproject.org/rpms/kakasi/raw/4756771/f/kakasi-configure-c99.patch";
+      hash = "sha256-XPIp/+AR6K84lv606aRHPQwia/1K3rt/7KSo0V0ZQ5o=";
+    })
+  ];
+
   postPatch = ''
     for a in tests/kakasi-* ; do
       substituteInPlace $a \