RFR(XS): 8193518: C2: Vector registers sometimes corrupted at safepoint

[Roland Westrelin]

Hi Tobias,

> The new TestVectorsNotSavedAtSafepoint.java fails on all platforms with "java.lang.OutOfMemoryError: Java heap space". I
> think this is due to the GarbageProducerThread allocating thousands of Objects:
>
> java.lang.OutOfMemoryError: Java heap space
> at TestVectorsNotSavedAtSafepoint$GarbageProducerThread.run(TestVectorsNotSavedAtSafepoint.java:54)

Thanks for running the tests. Can you try the new test?

http://cr.openjdk.java.net/~roland/8193518/webrev.01/

Roland.