Include vendor's problem list only if there is one

[sophia-guo]

Close #4790

Signed-off-by: Sophia Guo sophia.gwf@gmail.com

[karianna]

Even though those problems lists are empty, downstream providers may rely on them?

[sophia-guo]

Even though those problems lists are empty, downstream providers may rely on them?

If Vendors do need to exclude tests per their specific reason per JDK they can create directly add the files.

[smlambert]

@karianna - this PR contains a change in openjdk.mk that means empty vendor-specific ProblemList files are no longer needed as placeholders.

If downstream vendors have specific tests that need to be excluded, that are not in the common set of ProblemList files applicable to all vendors, then you can add the file back into the vendor specific ProblemList files with an entry in it. It makes no sense for us to force vendors to add empty files in order to run without error, so the change in the openjdk.mk file of the PR fixes that behaviour.