The instruction selection for following sequences is
improved:

  113: Word64Sar(107, 91) : Internal/Any
  114: TruncateInt64ToInt32(113) : Signed32/UntaggedSigned32
  115: ChangeInt32ToFloat64(114) : Signed32/UntaggedFloat64

TEST=unittests/InstructionSelectorTest.ChangesFromToSmi
BUG=

Review URL: https://codereview.chromium.org/1318153006

Cr-Commit-Position: refs/heads/master@{#30645}