mjsunit: Fix the error message produced by assertInstanceof.

mjsunit: Fix the error message produced by assertInstanceof.

Used to be:

Failure: expected <foo> is not an instance of <Bar> but of < Baz>> found <undefined>

Should be:

Failure: <foo> is not an instance of <Bar> but of <Baz>

BUG=

Committed: https://crrev.com/2a480eff395756f36eb0ae2fc0a573454b394268
Cr-Commit-Position: refs/heads/master@{#40319}

[marja, 2016-10-14 13:31:02]

marja@chromium.org changed reviewers:
+ verwaest@chromium.org

[marja, 2016-10-14 13:31:03]

ptal

[Toon Verwaest, 2016-10-14 13:36:21]

lgtm

[marja, 2016-10-14 13:40:09]

The CQ bit was checked by marja@chromium.org

[commit-bot: I haz the power, 2016-10-14 13:40:12]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-10-14 14:12:03]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-10-14 14:12:10]

Description was changed from

==========
mjsunit: Fix the error message produced by assertInstanceof.

Used to be:

Failure: expected <foo> is not an instance of <Bar> but of < Baz>> found
<undefined>

Should be:

Failure: <foo> is not an instance of <Bar> but of <Baz>

BUG=
==========

to

==========
mjsunit: Fix the error message produced by assertInstanceof.

Used to be:

Failure: expected <foo> is not an instance of <Bar> but of < Baz>> found
<undefined>

Should be:

Failure: <foo> is not an instance of <Bar> but of <Baz>

BUG=

Committed: https://crrev.com/2a480eff395756f36eb0ae2fc0a573454b394268
Cr-Commit-Position: refs/heads/master@{#40319}
==========

[commit-bot: I haz the power, 2016-10-14 14:12:11]

Patchset 1 (id:??) landed as
https://crrev.com/2a480eff395756f36eb0ae2fc0a573454b394268
Cr-Commit-Position: refs/heads/master@{#40319}

[marja, 2016-10-15 06:33:32]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/2421033003/ by marja@chromium.org.

The reason for reverting is: This is probably not working for falsey values. I
cannot JavaScript :P.