The HLO input/ouput alias config can be setup by the user, expecting a must

alias semantics, and opportunistically by the compiler.
Since the upper layer of the code will perform aliasing actions on their own,
based on the HLO input/output aliasing configuration, we need a way for the
upper layer to distringuish whether a given aliasing is coming from the user,
or the compiler.
This CL adds a single field to the alias data, to differentiate between user
and compiler/system aliases.

PiperOrigin-RevId: 228429740