hdf4: fix build on aarch64-darwin

This resolves #126156 by preventing the headers from confusing Linux
aarch64 with Apple. The package's own tests work fine without further
changes.

pkgs/tools/misc/hdf4/darwin-aarch64.patch

@@ -0,0 +1,11 @@
+--- a/hdf/src/hdfi.h	2021-06-16 16:31:31.000000000 +1200
++++ b/hdf/src/hdfi.h	2021-06-16 16:42:26.000000000 +1200
+@@ -1343,7 +1343,7 @@
+ #endif /* IA64 */
+ 
+ /* Linux AArch64 */
+-#if defined __aarch64__
++#if defined __aarch64__ && !defined __APPLE__
+ 
+ #ifdef GOT_MACHINE
+ If you get an error on this line more than one machine type has been defined.

pkgs/tools/misc/hdf4/default.nix

@@ -44,6 +44,7 @@ stdenv.mkDerivation rec {
       url = "https://src.fedoraproject.org/rpms/hdf/raw/edbe5f49646b609f5bc9aeeee5a2be47e9556e8c/f/hdf-aarch64.patch";
       sha256 = "112svcsilk16ybbsi8ywnxfl2p1v44zh3rfn4ijnl8z08vfqrvvs";
     })
+    ./darwin-aarch64.patch
   ];
 
   nativeBuildInputs = [