Revert "Add support to load/store byte fields." and "MIPS: Add support to load/store byte fields.".

Revert "Add support to load/store byte fields." and "MIPS: Add support to load/store byte fields.".

This reverts commit r17079 and r17085. Will reland after fix.

TBR=jkummerow@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=17099

[Benedikt Meurer, 2013-10-04 05:47:48]

Committed patchset #1 manually as r17099 (presubmit successful).

[Jakob Kummerow, 2013-10-04 08:24:11]

LGTM.

For the record, reverting this wouldn't have been necessary, since AFAICS the
buggy code was effectively unreachable. Oh well.