prefer predecessor frame states at merges
change assertions in VirtualObject to look at the LIRKind
better stamps for RightShiftNode
LoadHubNode is not Canonicalizable.Unary (beause of the guard)
support simplification in CustomCanonicalizer and turn it into an abstract class
cleanups and doc for PhiNode.singleValue
handle HotSpotCompressedNullConstant in graalCodeInstaller