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=

Review URL: https://codereview.chromium.org/13856011

Patch from Andy Wingo <wingo@igalia.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@14437 ce2b1a6d-e550-0410-aec6-3dcde31c8c00