RFR JDK-8059510 Compact symbol table layout inside shared archive

[Jiangli Zhou]

I've updated the webrev with unit tests:

  http://cr.openjdk.java.net/~jiangli/8059510/webrev.02/
http://cr.openjdk.java.net/~jiangli/8059510/webrev.02/test/runtime/SharedArchiveFile/DumpSymbolAndStringTable.java.html
http://cr.openjdk.java.net/~jiangli/8059510/webrev.02/test/runtime/SharedArchiveFile/SharedSymbolTableBucketSize.java.html

Thanks,
Jiangli