0b833d4977
implemented by extending the existing support for stack overflow checking in the vm. When an interrupt is scheduled for an isolate, we overwrite the isolate's stack limit with a value guaranteed to cause a stack overflow. We support multiple kinds of interrupts, encoded in the low bits of the stack limit. Add Dart_InterruptIsolate and Dart_InterruptIsolateCallback to the dart embedding api to allow the embedder to request and handle interrupts. Add EXPECT_SUBSTRING(needle, haystack) testing macro. Review URL: http://codereview.chromium.org//8851008 git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@2529 260f80e4-7a28-3924-810f-c04153c831b5