openspades, arangodb: more #include error fixups

... after gcc-5.4.

pkgs/games/openspades/default.nix

@@ -20,6 +20,7 @@ stdenv.mkDerivation rec {
       --replace "isnan(" "std::isnan(" --replace "isinf(" "std::isinf("
     sed '1i#include <cmath>' -i Sources/Client/{Player,Client_Input,Corpse}.cpp \
       -i Sources/Draw/SWMapRenderer.cpp
+    sed '1i#include <math.h>' -i Sources/Draw/SWFeatureLevel.h
   '';
 
   nativeBuildInputs = 

pkgs/servers/nosql/arangodb/default.nix

@@ -11,6 +11,13 @@ stdenv.mkDerivation rec {
     sha256 = "1v07fghf2jd2mvkfqhag0xblf6sxw7kx9kmhs2xpyrpns58lirvc";
   };
 
+  postPatch = ''
+    substituteInPlace 3rdParty/V8-3.31.74.1/build/gyp/gyp --replace /bin/bash ${bash}/bin/bash
+    substituteInPlace 3rdParty/etcd/build --replace /bin/bash ${bash}/bin/bash
+    sed '1i#include <cmath>' -i arangod/Aql/Functions.cpp \
+      -i lib/Basics/string-buffer.cpp
+  '';
+
   buildInputs = [
     openssl zlib python gyp go readline
   ];
@@ -19,12 +26,6 @@ stdenv.mkDerivation rec {
 
   NIX_CFLAGS_COMPILE = "-Wno-error=strict-overflow";
 
-
-  patchPhase = ''
-    substituteInPlace 3rdParty/V8-3.31.74.1/build/gyp/gyp --replace /bin/bash ${bash}/bin/bash
-    substituteInPlace 3rdParty/etcd/build --replace /bin/bash ${bash}/bin/bash
-    '';
-
   enableParallelBuilding = true;
 
   meta = with stdenv.lib; {