Relax --debug-code checks that runtime returns are not the hole

Relax --debug-code checks that runtime returns are not the hole

ia32, unlike the other architectures, includes a --debug-code check that
asserts that runtime functions do not return the hole.  However the new
SuspendJSGeneratorObject runtime does return the hole at times.

This CL adds a wee hack that only signals an error if the callee was not
SuspendJSGeneratorObject.

R=mstarzinger@chromium.org
BUG=

Committed: http://code.google.com/p/v8/source/detail?r=14437

[Michael Starzinger, 2013-04-25 10:39:57]

LGTM with a comment. I'll land this one comment is addressed.

https://codereview.chromium.org/13856011/diff/1/src/ia32/code-stubs-ia32.cc
File src/ia32/code-stubs-ia32.cc (right):

https://codereview.chromium.org/13856011/diff/1/src/ia32/code-stubs-ia32.cc#n...
src/ia32/code-stubs-ia32.cc:5047: // However, it is expected that
SuspendJSGeneratorObject returns the hole.
I am fine with landing this white-listing for now to make tests pass. But can we
add a TODO here to use another sentinel (e.g. a Harmony symbol) instead? This
has really low priority, it would just be "nice to have".

[wingo, 2013-04-25 10:54:03]

Updated patch adds TODO at the site of the hack.

[Michael Starzinger, 2013-04-25 12:00:13]

Committed patchset #2 manually as r14437 (presubmit successful).