This makes it possible for binfmt_misc to optionally preserve the
contents of argv[1].  This is needed for building accurate simulators
which are invoked via binfmt_misc.  I had brought up this patch a while
ago (see URL below) and there was no negative feedback (OK, there was no
feedback at all...  ;-).

The patch is trivial and the new behavior is triggered only if the
letter "P" (for "preserve") is appended to the binfmt_misc registration
string, so it shold be completely safe.