pv-runtime: Use a SrtSysroot to represent the real root
We will want this later, to be able to pass it to interfaces that have been converted to take a SrtSysroot. No functional change.
Common prerequisite for !602 (merged) and !616 (merged).
We will want this later, to be able to pass it to interfaces that have been converted to take a SrtSysroot. No functional change.
Common prerequisite for !602 (merged) and !616 (merged).