Review request for JDK- 8006220 Faster creation of properties

[Jim Laskey]

Please review http://cr.openjdk.java.net/~jlaskey/8006220/webrev.00/index.html .  This is the preliminary work for lighter weight PropertyMaps.  The most significant changes here are the introduction of slot to basic properties, elimination of embedded fields and the elimination of SpillProperties (merged with AccessorProperty.)

As it stands, this seems to make octane slightly faster, likely due to more aggressive embedding of spill fields.  Results may vary.