Rename buildNativeInputs -> nativeBuildInputs

Likewise for propagatedBuildNativeInputs, etc.  "buildNativeInputs"
sounds like an imperative rather than a noun phrase.

pkgs/development/libraries/gmp/4.3.2.nix

@@ -8,7 +8,7 @@ stdenv.mkDerivation rec {
     sha256 = "0x8prpqi9amfcmi7r4zrza609ai9529pjaq0h4aw51i867064qck";
   };
 
-  buildNativeInputs = [ m4 ];
+  nativeBuildInputs = [ m4 ];
 
   # Prevent the build system from using sub-architecture-specific
   # instructions (e.g., SSE2 on i686).

pkgs/development/libraries/gmp/5.0.5.nix

@@ -10,7 +10,7 @@ stdenv.mkDerivation rec {
 
   patches = [ ./ignore-bad-cpuid.patch ];
 
-  buildNativeInputs = [ m4 ];
+  nativeBuildInputs = [ m4 ];
 
   configureFlags =
     # Build a "fat binary", with routines for several sub-architectures