Fix bogus reset of store buffer top in deserializer.

Fix bogus reset of store buffer top in deserializer.

This was originally introduced in r6201 because the store buffer top is
part of the root set and treated as SMI, which in turn causes it to be
overwritten by the deserializer. A better fix was introduced in r6443
and skips the entry instead of restoring it after deserialization, thus
making this reset obsolete.

R=erik.corry@gmail.com
BUG=v8:1562
Committed: http://code.google.com/p/v8/source/detail?r=9221

[Michael Starzinger, 2011-09-09 16:42:47]

PTAL.

[Erik Corry, 2011-09-12 07:14:58]

LGTM.  Thanks for figuring this out.