RFR(S): [testbug] add @requires vm.cds to CDS tests in jdk test suite

[Lindenmaier, Goetz]

Hi,

Could I please get a review for this small fix to the tests?
http://cr.openjdk.java.net/~goetz/wr17/8186719-cdsRequires/webrev.01/

I introduces property @requires vm.cds in the hotspot test suite, and 
now identified three tests in the jdk suite that require the same.

Best regards,
 Goetz.