WIP: Add new tests for new options

[AlenBadel]

Adding tests for -XX:[+/-]UseLargePages, and -XX:LargePageSizeInBytes=<size>.

[gita-omr]

@smlambert I am looking at the changes, but could you please review as well?

[gita-omr]

I think overall coverage is good. I just found the existing naming (before this PR) of the directories a bit confusing:
test/xlp
test/xlpcodecache

Could we rename them into :
test/heappages
test/codecachepages
?

Also not sure if I saw a test for codecache where -Xlp follows -XX options, since -Xlp only partially overrides -XX. But maybe I missed it.

[smlambert]

@AlenBadel - can you resolve the conflict in your PR please (which I think is introduced because your other PR #8025 is now merged), thanks!

[AlenBadel]

@smlambert My apologies, this PR will need to wait while #7476 purposes some changes on additional options. Mainly, adding -XX:-UseLargePages. I'll update this PR when everything is straightened out.

[smlambert]

Yes thanks, sounds good @AlenBadel !

[genie-openj9]

Can one of the admins verify this patch?