RFR (S): 8214086: [TESTBUG] Fix subgraph test cases in ReplaceCriticalClasses.java

[Jiangli Zhou]

Please review the following test fix in ReplaceCriticalClasses.java. I 
re-implemented the subgraph check to verify a subgraph is not used at 
runtime if one of it's klass (who's object is contained within the 
archived subgraph) is changed by the JVMTI agent.

I added a test case for the newly archived Long cache subgraph. Since 
both ResolvedModule and Long classes are loaded during the primordial 
phase, '-early -notshared' are set in those test cases.

As part of the change, I fixed 
HeapShared::initialize_from_archived_subgraph to only do the logging 
output after sbugraph(s) is successfully installed in the given Klass.

webrev: http://cr.openjdk.java.net/~jiangli/8214086/webrev.00
bug: https://bugs.openjdk.java.net/browse/JDK-8214086

Tested ReplaceCriticalClasses.java locally on linux-x64. Will run 
tier1-tier2.

Thanks,
Jiangli