So far we've been using ldr/str (32-bit) to load/store
the whole stack slot, independent of the variable type.

Toggle on some tests that didn't have an Om1 variant
previously. Didn't toggle everything since there are still
some problems with liveness from code being unimplemented.

BUG= https://code.google.com/p/nativeclient/issues/detail?id=4076
R=stichnot@chromium.org

Review URL: https://codereview.chromium.org/1144923008