This changes all direct function calls in Crankshaft to pass undefined
via the register expected to hold the new.target value. Note that the
register is still ignored by all callees for now.

This is a preparatory CL to allows us passing new.target in a register
instead of via a side-channel through the construct stub frame.

R=bmeurer@chromium.org
BUG=v8:4544
LOG=n

Review URL: https://codereview.chromium.org/1459183002

Cr-Commit-Position: refs/heads/master@{#32125}