[9] RFR 8150850: [JVMCI] NPE when executing HotSpotConstantReflectionProvider.readStableFieldValue

[Doug Simon]

Looks good.

> On 14 Mar 2016, at 13:02, Konstantin Shefov <konstantin.shefov at oracle.com> wrote:
> 
> Hello
> 
> Please review a bug fix in JVMCI jdk.vm.ci.hotspot.HotSpotConstantReflectionProvider::readStableFieldValue method. 
> 
> When one executes HotSpotConstantReflectionProvider::readStableFieldValue method for an instance field and JavaConstant.NULL_POINTER as a receiver, it throws an NPE. However, the javadoc says it should return null. 
> 
> E.g. when we execute method HotSpotConstantReflectionProvider::readFieldValue for an instance field and JavaConstant.NULL_POINTER as a receiver, we get null as expected.
> 
> Additional check should be added for null as the first argument.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8150850
> Webrev: http://cr.openjdk.java.net/~kshefov/8150850/webrev.00
> 
> Thanks
> -Konstantin