This is IA32 only for now.

Added a random value to each assembler instance (JIT cookie) to be used for constant splitting. Added safe versions of setting a register with an immediate value and for pushing an immediate value. Used these functions where user controlled immediate values could be emitted in the code stream. I also used it for immediates which are an argument number even though the number of formal arguments is currently limited to 16k.

I found no compares directly with user controlled constants.

I am not sure whether the test is that useful, but it might catch some changes missing constant splitting.

Review URL: http://codereview.chromium.org//7005031

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7868 ce2b1a6d-e550-0410-aec6-3dcde31c8c00