Source updates for tool compatibility and function

[openpowerwtf]

There are source updates that should be done to aid using the current open tool environment. See openpower-cores/a2i#43 (attributes provided info for old verif/PD toolchains).

Any preferences as to creating a separate dev subtree for all new updates (retain rel as-is), or just updating in-place (the 'modern' way 😄 )?

There are potentially functional changes also (I have not tested the many generic settings to see if they compile and function as expected).