Reland "Trigger exception debug event for promises at the throw site."

Reland "Trigger exception debug event for promises at the throw site."

R=rossberg@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=21097

[Yang, 2014-04-30 15:12:18]

Second patch set is the fix. I was naive. It turns out that we could actually
get reentry, so that a stack of stored stack handlers and promise getters is
necessary.

[Yang, 2014-04-30 15:13:32]

https://codereview.chromium.org/266533003/diff/20001/src/debug.cc
File src/debug.cc (right):

https://codereview.chromium.org/266533003/diff/20001/src/debug.cc#newcode1334
src/debug.cc:1334: if (promise_catch_handlers_.length() == 0) return;
This is to make the fuzzer happy. It just calls runtime functions without caring
about prologue/epilogue pairings.

[rossberg, 2014-04-30 15:16:34]

lgtm

[Yang, 2014-04-30 15:18:23]

Committed patchset #2 manually as r21097 (presubmit successful).