split DebugHistogram printing out into separate service
added DebugHistogram printer that emits R statements to instantiate a vector of named values corresponding to the histogram
replaced computed internal name for java.lang.System with a constant to workaround deadlock issue involving class initializer of HotSpotResolvedJavaField (CR-1405)
Truffle-DSL: fixed a if bug target parameters and executes accidently do not match.

--HG--
extra : rebase_source : 9058a58c9b8fbb06ec4149e1e140e4749047d06b
added support for DebugMetric and DebugTimer objects to be unconditionally enabled (GRAAL-195)
removed side effect of -XX:+CITime on -G:Meter and -G:Time (GRAAL-195)
re-enabled -G:+DumpOnError
Try constant folding in canonicalizer even if tryInferStamp didn't change anything.
Graph: fix index of array access in usageModCount()

--HG--
extra : rebase_source : 3310ded6d186972b1ce7554ee7109f9e9056f4df
fix usage of IterableNodeType, as some verions of javac seems to have problems with it

--HG--
extra : rebase_source : 511596af81064b0302a2ed5a0bfb41cfe948f0e2
extra : amend_source : 01efd8e14b89e7ac804d136ec1d91e29b5ea3571
Truffle-DSL: allow multiple implicit casts with the same source type.

--HG--
extra : amend_source : 4b9e650f6cde636b51cd655e8efdb7c30ea794d9
updated README_GRAAL.txt to reflect recent mx changes
made methods for accessing HotSpot VM options static so they can be used without a HotSpotVMConfig object
fix spelling error
ensure Debug.enable() is called before any DebugTimer or DebugMetric objects are requested
The lowering of FixedGuardNode is independent of the runtime

--HG--
extra : rebase_source : 25c0983b5aa959d93b7df625f982d8d844a921af
Replace the many asNode methods with one on ValueNode and one on FixedNode

--HG--
extra : rebase_source : c0c26926addef18f6c503f6086e6442f5e803ade
New methods for incremental canonicalization.
Rename LoweringType to GuardsPhase and make it an attribute of StructuredGraphs

--HG--
extra : rebase_source : 0667dcf345ac981fa2ccd03b5fb779b64dab944d
Use CanonicalizerPhase.applyIncremental in InliningPhase.