This patch includes the following changes.
     1, Enable the turbofan backend support for X87 platform. It depends on previous CL: 3fdfebd2.
     2, Enable the test cases which are disabled because turbofan for X87 was not enabled.

BUG=v8:4135
LOG=N

Review URL: https://codereview.chromium.org/1179763004

Cr-Commit-Position: refs/heads/master@{#29049}