Fix module.map to not include missing header

This is actually a clang bug that's still present upstream at the time of
writing; the module.map refers to an "anm_neon.h" file that doesn't actually
exist in the folder.

Fixes #769

python/clang_includes/module.map

@@ -4,16 +4,6 @@ module _Builtin_intrinsics [system] {
     header "altivec.h"
   }
 
-  explicit module arm {
-    requires arm
-
-    explicit module neon {
-      requires neon
-      header "arm_neon.h"
-      export *
-    }
-  }
-
   explicit module intel {
     requires x86
     export *