RFR (XXS): 8066473: Port timeout utils from jdk test library into hotspot

[Pavel Chistyakov]

Hi all,

please review changes for: https://bugs.openjdk.java.net/browse/JDK-8066473
webrev: 
http://cr.openjdk.java.net/~iignatyev/pchistyakov/8066473/webrev.00/ 
<http://cr.openjdk.java.net/%7Eiignatyev/pchistyakov/8066473/webrev.00/>

We need some timeout staff that exists in jdk testlibrary in hotspot tests.
This fix ports DEFAULT_TEST_TIMEOUT constant and adjustTimeout method.

Testing: manual

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Thanks,
Pavel