The interpreter used a ZoneVector<WasmVal> to model the value stack.
Thus, at each single pop to the stack, a bounds check was performed,
and the storage was potentially extended.
This CL changes this to pre-allocate enough space for the stack of a
function when a new frame is entered. This avoids any checks for pushs
and pops.
Instead of storing a ZoneVector<WasmVal>, we store WasmVal* directly.
The maximum value stack size is precomputed together with the control
transfer side table.

This CL speeds up interpreted execution by 15% on average (measured
locally on a Z840).

R=ahaas@chromium.org
BUG=v8:5822

Change-Id: If949f7ee5233d874cd6a04b7dde2d7b4a95e45ea
Reviewed-on: https://chromium-review.googlesource.com/488061
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44902}