This makes sure that the coercion of global import values to numbers
remains non-observable to JavaScript. It allows instantiation failures
to fall back to JavaScript proper without accidentally causing some
side-effect to happen twice. Also coercions might invalidate previous
checks done during linking or throw exceptions.

R=clemensh@chromium.org
TEST=mjsunit/regress/regress-6431
BUG=v8:6431

Change-Id: Ibe2f7a336bc0fb25532d526746ecc802e04bbd5c
Reviewed-on: https://chromium-review.googlesource.com/512544
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46051}

This makes sure that property lookups on the provided imports object are
non-observable to JavaScript. It allows instantiation failures to fall
back to JavaScript proper without accidentally calling accessors twice.
Also accessors might invalidate previous checks done during linking or
throw exceptions.

R=clemensh@chromium.org
TEST=mjsunit/regress/regress-crbug-719384
BUG=chromium:719384

Change-Id: I3db2672d2a496110f705d02b82878e70cd5d701f
Reviewed-on: https://chromium-review.googlesource.com/509552Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45481}

This tests and fixes validation failures caused by assignments to
variables holding functions references (which are all considered
immutable). Such references can come from "stdlib" or "foreign".

R=clemensh@chromium.org
TEST=mjsunit/asm/global-imports
BUG=chromium:719382

Change-Id: Ic02be765e0773a6cc74a54e11a09d42ffb683cb8
Reviewed-on: https://chromium-review.googlesource.com/500188Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45189}

R=clemensh@chromium.org
BUG=v8:6127

Change-Id: I104bf807d3da6a9f269e4f729b254bc6a0d2f0df
Reviewed-on: https://chromium-review.googlesource.com/496206Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45098}

This also removes a broken optimization regarding immutable (i.e. const)
global variables. For now mutable and immutable global variables are
treated the same and hence copied during module initialization.

R=rossberg@chromium.org
TEST=mjsunit/asm/global-imports
BUG=v8:6279

Change-Id: I020fc12036dc534f5a62fb43f5c6fdb252314e62
Reviewed-on: https://chromium-review.googlesource.com/483360Reviewed-by: Andreas Rossberg <rossberg@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44763}