[turbofan] Use "leal" in even more situations

Achieve more than parity with modes currently handled on ia32 in preparation for
porting the entire mechanism to ia32, including supporting mul of constants 3,
5 and 9 with "leal" instructions.

TEST=unittests

Review URL: https://codereview.chromium.org/774193003

Cr-Commit-Position: refs/heads/master@{#25677}