Add deoptimization environments to instructions.

Add deoptimization environments to instructions.

Each instruction that can deoptimize need to have the values of the
non-optimizing code as uses. The values are stored in an environment
(GrowableArray<Value*>) attached to the instruction when constructing
SSA form.

For now every instructions gets a deoptimization environment. It contains
the values of all locals, parameters and expression stack elements at
the start of the instruction.

The environment is not used yet, but can be printed in the flow graph
with the flag --print-environments.
Committed: https://code.google.com/p/dart/source/detail?r=9345

[Vyacheslav Egorov (Google), 2012-07-03 12:40:31]

lgtm