a reason to stack allocate large chunks of stack space.
- Runtime_GetCFrames used to allocate a frame size of 52040 bytes.
- PreallocatedMemoryThread::Run used to allocate 32784 bytes.
- Fixed StringStream overflow conditions.

Review URL: http://codereview.chromium.org/67197

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1729 ce2b1a6d-e550-0410-aec6-3dcde31c8c00