RFR: 8156759: [JVMCI] remove JVMCIError and UnsafeUtil classes

[Doug Simon]

After some internal discussion, I’m going to withdraw this RFE. Instead, I’ll generate a “JVMCI cleanup” RFE that among other changes:

- preserves JVMCIError in jdk.vm.ci.common (but removes the context functionality)
- moves InitTimer to jdk.vm.ci.common (getting rid of at least one single class project)

-Doug

> On 12 May 2016, at 09:42, Doug Simon <doug.simon at oracle.com> wrote:
> 
> 
>> On 11 May 2016, at 22:54, Christian Thalinger <christian.thalinger at oracle.com> wrote:
>> 
>> 
>>> On May 11, 2016, at 10:19 AM, Doug Simon <doug.simon at oracle.com> wrote:
>>> 
>>> Please review this change which removes a couple of classes which do not need to be in JVMCI.
>>> 
>>> I’ve also taken the liberty of including a change that updates the mx Java compliance level for all JVMCI projects to 9 since JDK9 API (e.g., java.lang.reflect.Module) is now used in JVMCI. This means building with mx has been broken since that API usage was introduced. I can pull this out into a separate RFE if necessary but am hoping it can piggy back on this bug.
> 
> I’ve removed the above changes from the webrev.
> 
> -Doug