Fix a bug when creating a HDeoptimization instruction.

We need to copy the environment, instead of just pointing
to an existing one. Otherwise, if the instruction that initially
holds the environemnt gets removed from the graph, any update
to an instruction in that environment will not be reflected in it.

bug:20058506

Change-Id: I2a62476d0851ecbc3707c0da395d8502ee437422