This replaces Runtime_RunMicrotasks with Runtime_PerformMicrotaskCheckpoint.

RunMicrotasks forcibly runs Microtasks even when the microtasks are suppressed,
and may causes nested Microtasks in a problematic way. E.g. that confuses
v8::MicrotasksScope::IsRunningMicrotasks() and GetEnteredOrMicrotaskContext().

OTOH, PerformMicrotaskCheckpoint() doesn't run cause the failure as it
respects the microtask suppressions.

As all existing tests don't call RunMicrotasks() in the suppressed situation
(like Promise.resolve().then(()=>{%RunMicrotasks();})), this change should
not affect to these tests.

Change-Id: Ib043a0cc8e482e022d375084d65ea98a6f54ef3d
Reviewed-on: https://chromium-review.googlesource.com/c/1360095Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Taiju Tsuiki <tzik@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58068}

Without this the call to `formatFailureText` in `test-async.js`
fails but goes unnoticed since the promise change is rejects
which is not handled.  And d8 silently ignores the the unhandled
rejections.

Once `formatFailureText` was added it reveals a but where several
tests were expecting `.equal` to be a deepEquals.  Specifically:

test/mjsunit/es6/promise-all.js
test/mjsunit/harmony/async-generators-resume-return.js
test/mjsunit/harmony/async-generators-return.js
test/mjsunit/harmony/async-generators-yield.js

Making equals call `deepEquals` fixed that issue.

Change-Id: I350c7d916147eaa7cf873bdaf273aebbaaa833c5
Reviewed-on: https://chromium-review.googlesource.com/1236852
Commit-Queue: Sam Clegg <sbc@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56107}

The original implementation of 'testAsync' in mjsunit.js required to
put the call to '%AbortJS' into an 'eval' statement. The reason is that
this call requires the flag --allow-natives-syntax to be set, but the
flag is not set in all mjsunit tests. With the use of 'eval'
compilation errors can be avoided.

The problem with this approach was that the fuzzer started to produce
test cases which include the line 'eval("%AbortJS(message)");', and
this line crashes intentionally. Different to the line
'%Abort(message)', however, the 'eval' statement cannot be filtered
so easily in the fuzzer. Therefore I pulled the implementation of
'testAsync' into a separate file to avoid the 'eval'.

Additional changes: I use '===' now instead of 'deepEquals' in
AsyncAssertion.equals because 'deepEquals' is not available outside
mjsunit.js. Using '===' seems more appropriate anyways because for
all tests but one it is sufficient, and it is more precise than
deepEquals.

R=gsathya@chromium.org

Bug: chromium:774841
Change-Id: I47270aa63ff5a1d6aa76a771f9276eaaf579c5ac
Reviewed-on: https://chromium-review.googlesource.com/1156598Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54833}