RFR 8143015/9: 5 tests fail with error "Can't find source for class: java.util.stream.OpTestCase"

[Felix Yang]

Hi,
    please review the following fix for 5 broken test cases, which was 
introduced by JDK-8142996. These tests refer with 
java.util.stream.OpTestCase, which was relocated from 
test/java/util/stream/bootlib/ to test/java/util/stream/bootlib/java.base/

Bug: https://bugs.openjdk.java.net/browse/JDK-8143015
Webrev: http://cr.openjdk.java.net/~xiaofeya/8143015/webrev.00/

Thanks,
Felix