Done rely on C++ object padding across platforms

Don't rely on C++ object padding across platforms

The use of sizeof on FrameDescription to get to the additional allocated memory for the frame content relies on the padding of the FrameDescription. On IA32 Linux the FrameDescription is not padded but on ARM Linux it is padded to become 8 byte aligned. With a snapshot generated with the ARM simulator on IA32 Linux that contains one or more of the deoptimization tables the deoptimization did not work as the access to the frame content was one off between the C++ code and the generated code.

R=ager@chromium.org
Committed: http://code.google.com/p/v8/source/detail?r=7369

[Mads Ager (chromium), 2011-03-25 13:25:53]

LGTM