jimage refresh excluded tests

these tests need to be re-enabled
test/java/nio/Buffer/LimitDirectMemory.sh
test/java/nio/file/spi/SetDefaultProvider.java

LimitDirectMemory.sh then the test needs to be adjusted to take account of the direct buffers that the jimage code is created.

SetDefaultProvider.java test is more tricky because interposing on the default provider with this version of jimage code will lead to recursive initialization issues. Once we get to one jimage file and replacing the ext/app class loaders then it will become a non-issue and we liberate the test then.