Add other gdb-supported platforms that run on allowed arches.

Author: jvennix-r7

modules/exploits/multi/gdb/gdb_server_exec.rb

@@ -21,8 +21,7 @@ def initialize(info = {})
         [ 'x86 (32-bit)',    { 'Arch' => ARCH_X86 } ],
         [ 'x86_64 (64-bit)', { 'Arch' => ARCH_X86_64 } ]
       ],
-      'Arch'          => [ ARCH_X86, ARCH_X86_64 ],
-      'Platform'      => %w(linux),
+      'Platform'      => %w(linux unix osx windows),
       'DefaultTarget' => 0
     ))
   end