Fix release VPS build failure in linux injector

instrlist_disassemble() is only available in DEBUG, INTERNAL, or
CLIENT_INTERFACE builds.

Also move instrlist_disassemble() from arch_exports.h to disassemble.h.
This seemed consistent with instr_disassemble() and opnd_disassemble()
and won't affect the generated API headers.

Review URL: https://codereview.appspot.com/7305050

git-svn-id: https://dynamorio.googlecode.com/svn/trunk@1882 49cc7528-f6fd-11dd-9d1a-b59b2e1864b6