JDK 9 RFR of JDK-8151511: Test case in CollectionAndMapModifyStreamTest for LinkedHashMap overrides that for HashMap

[Amy Lu]

Please review the patch for fixing typo in steam tests:

bug: https://bugs.openjdk.java.net/browse/JDK-8151511
webrev: http://cr.openjdk.java.net/~amlu/8151511/webrev.00/

1) In CollectionAndMapModifyStreamTest.java
maps.put(HashMap.class.getName(), () -> new LinkedHashMap<>(content));
should be
maps.put(LinkedHashMap.class.getName(), () -> new LinkedHashMap<>(content));

2) ThowableHelper.java renamed to ThrowableHelper.java

Thanks,
Amy