Verify proper API use of acquire/release typed data

In this first version, we just track the set of objects and verify that calls to release match. The next step is to copy the data to a side buffer, which is then unmapped on release to catch use-after-release bugs.

Explicitly disallow nested acquires, since the visibility of writes would depend on whether data is acquired in-place.

Also explicitly disallow other access to the data (e.g., trough list accessors) for the same reason.

R=asiva@google.com

Committed: https://code.google.com/p/dart/source/detail?r=43575

[koda, 2015-02-06 20:39:32]

koda@google.com changed reviewers:
+ asiva@google.com

[siva, 2015-02-06 21:13:00]

LGTM.

I was wondering if we should also safe guard against shutting down an Isolate
with open acquires, we could ponder on this for later.

[koda, 2015-02-06 22:31:52]

Committed patchset #4 (id:60001) manually as r43575 (presubmit successful).