Add %EBP/%RBP to the set of registers for which redundant-PUT

Add %EBP/%RBP to the set of registers for which redundant-PUT
elimination is not done.  This is needed so that Valgrind can
construct correct stack traces on x86/amd64.  Curiously enough old
UCode valgrind didn't do this correctly, but because it doesn't
optimise as aggressively as Vex, we didn't notice this.  Overall
result is that Vex-based valgrind now produces more accurate stack
traces, at least on x86, than valgrind-2.4.X will.

git-svn-id: svn://svn.valgrind.org/vex/trunk@1042