This passes the new.target value in a register instead of through a
side-channel via the construct stub. The interpreter entry trampoline
stores this value in a bytecode register so that it can be accessed
directly by the interpreter. The size of the interpreter stack frame
hence grows by one slot.

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

Review URL: https://codereview.chromium.org/1469313002

Cr-Commit-Position: refs/heads/master@{#32264}