Uses the JavaScript BigInt Object to represent Wasm's 64bits integers.
Attention, 32 bits architectures are not supported yet.

Bug: v8:7741
Change-Id: I28b718fa567bca5103b2f38a879049cd20a46f12
Reviewed-on: https://chromium-review.googlesource.com/c/1355144
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58152}

See the WebAssembly bulk memory proposal here:
https://github.com/WebAssembly/bulk-memory-operations

This initial CL adds a wasm experimental flag:
`--experimental-wasm-bulk-memory`, and also parsing of passive segments.

A passive segment is one that is not copied into the table/memory on
instantiation, but instead later via the `{table,memory}.init`
instructions.

The binary format of passive data segments is unlikely to change, but
the format for passive element segments may change (see
https://github.com/WebAssembly/bulk-memory-operations/pull/39).

Bug: v8:7747
Change-Id: I2a7fb9bc7648a722a8c4aab4185c68d3d0843858
Reviewed-on: https://chromium-review.googlesource.com/c/1330015
Commit-Queue: Ben Smith <binji@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57451}

This CL introduces a set of configuration options implemented as
a struct of booleans that together comprise the set of enabled
or detected features. The configuration options replace command-line
flags that were checked deep in the implementation. As such, it is
necessary to plumb them through multiple levels of abstraction.

R=ahaas@chromium.org
CC=mstarzinger@chromium.org
BUG=chromium:868844

Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: I1b82f5826e4fd263f68e8cafcd923bac5818a637
Reviewed-on: https://chromium-review.googlesource.com/1163670Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55018}