Investigate use of xlc17 for AIX builds

[sxa]

Related: https://github.com/adoptium/adoptium-support/issues/824#issuecomment-1753328083

We have some interest in building AIX with xlc17 instead of xlc16. The link above indicates that a customer believes they have some issues related to JNI when the JDK is built with xlc16. There has been some upstream resistance to the change to switch over to requiring C++17 (therefore xlc17) by default although it looks like SAP has successfully built the JDK with xlc17.

We should pre-empt a change in the future by looking at installing xlc17 and verifying that it works on our existing build systems, which could also allow us to supply pre-release test builds (unsupported, untested etc. for now) with that compiler to users who desire them.