Adds a virtual method, GetFreshIds(), to Transformation. Every
transformation uses this to indicate which ids in its protobuf message
are fresh ids. This means that when replaying a sequence of
transformations the replayer can obtain a smallest id that is not in
use by the module already and that will not be used by any
transformation by necessity. Ids greater than or equal to this id
can be used as overflow ids.
Fixes#3851.
This transformation takes an OpSelect instruction and replaces it with
a conditional branch, selecting the correct value using an OpPhi
instruction.
Fixes part of the issue #3544.
Alastair Donaldson
Alastair Donaldson
Stefano Milizia