Ensure that interruptor callback registered through API is called outside of ExecutionAccess lock.

Such a coarse locking can cause a dead-lock when another thread is attempting to clear an interrupt while we are waiting in the interrupt callback.

Add test that verifies this API invariant.

BUG=chromium:374978
LOG=N
R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/291123002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21376 ce2b1a6d-e550-0410-aec6-3dcde31c8c00