RFR(M) JDK-8031819: Remove legacy jdk checks and code

[harold seigel]

Hi Dan,

It look like even with this change Hotspot 9 may still work with JDK 8:

      % $JAVA_HOME/bin/java -version
    java version "1.8.0-ea"
    Java(TM) SE Runtime Environment (build 1.8.0-ea-b121)
    Java HotSpot(TM) Server VM (build 1.9.0-internal-fastdebug, mixed mode)

Harold

On 6/6/2014 9:07 AM, Daniel D. Daugherty wrote:
> On 6/5/14 11:26 PM, David Holmes wrote:
>
> > But everyone needs to be very aware that once this goes in you
> > can forget about placing a JDK 9 VM anywhere but a JDK 9 JDK.
> > (Or did we already hit that?)
>
> This caught my eye... Have we already reached a point where we
> can't put the current JDK9 JVM into various JDK8 builds? I know
> we have restrictions about putting the current JVM (and the
> HSX-25 JVM) into JDK7...
>
> If the current JDK9 JVM (prior to this changeset) can still be
> dropped into JDK8 and this changeset makes it so that the JDK9
> JVM can no longer be dropped into JDK8, then we need to get
> wider feedback than hotspot-runtime-dev at ...
>
> In particular, the HotSpot Compiler and Performance teams should
> be notified since dropping the current JVM into an older JDK is
> one of their standard failure analysis techniques; don't know
> if the HotSpot GC team does that trick much.
>
> Dan