RFR (S) 8221967: InternTest.java timed out

[coleen.phillimore at oracle.com]

Summary: Move redundant table lookup and make rehashing be a needed 
guaranteed safepoint cleanup action.

The String Hashtable wasn't getting rehashed because 
GuaranteedSafepointInterval didn't think it had to do anything. Plus, 
there's an extra lookup in both symbol because of the fix for 
JDK-8216049 <https://bugs.openjdk.java.net/browse/JDK-8216049>.

The test is in Oracle closed so the CR is closed.  The test was run 100 
times without timeouts on solaris sparc, where the original problem 
happened.  Hotspot tier1-3 testing is in progress.

8221967: InternTest.java timed out
Summary: Move redundant table lookup and make rehashing be a needed 
guaranteed safepoint cleanup action.

Thanks,
Coleen