a573d2dec8
Eliminate Boxing/Unboxing pairs. Allow boxing, unboxing and double binary operations to participate in CSE. Allow double comparisons to operate on unboxed inputs. Support XMM registers and double spill slots in deoptimization. Save XMM registers when calling to runtime from WriteBarrier stub. R=srdjan@google.com BUG= Review URL: https://chromiumcodereview.appspot.com//10919008 git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@11652 260f80e4-7a28-3924-810f-c04153c831b5