[PATCH] fixed compilation v8 on mips

Issue appears in https://github.com/crosswalk-project/v8-crosswalk/commit/e9da1c91fe411d3ae67a51c0433f3bf672572475
which does not update mips architecture.

Fixed by bringing back double_registers_ needed in deoptimizer-mips.cc

Signed-off-by: Vasyl Vavrychuk <vasyl.vavrychuk@globallogic.com>