Deprecate DTrace support

[Vladimir Kozlov]

Hi

The question about dropping DTrace support in HotSpot VM rose during discussion 8278423: "ExtendedDTraceProbes should be 
deprecated" [1].

It is not clear for me about Oracle support for it after we dropped SPARC. Do we still need to support it or we can drop 
it (remove code from HotSpot)?

Thanks,
Vladimir K

[1] https://bugs.openjdk.java.net/browse/JDK-8278423