Move Z CS support out of OMR and into OpenJ9

[fjeremic]

The CS support currently in OMR is very VM dependent. For example the J9GSParamenters struct that is reference throughout the implementation is only defined in OpenJ9 [1] [2]. Furthermore the software based implementation of CS in OMR relies on offsets in J9VMThread which are very VM specific and also relies on specific implementation details within OpenJ9.

As such we need to migrate our implementation from OMR and into OpenJ9 by making use of the new read barrier IL introduced by the x86 codegen team as part of the x86 software CS implementation in #3054.

This will involve adding new evaluators on Z and removing the "tree anchoring" hack that we currently do in OMR.

[1] https://github.com/eclipse/openj9/blob/3acd9df17c63a61eed8c329b6e250e22c0fe5f89/runtime/oti/j9nonbuilder.h#L5000-L5003
[2] https://github.com/eclipse/openj9/blob/90844424cf6b415acebc4916cea72e3fc6978b0f/runtime/oti/j9port_generated.h#L119-L130

[fjeremic]

Fixed as part of #5183.