RFR: 8148507: [JVMCI] mitigate deadlocks related to JVMCI compiler under -Xbatch

[Christian Thalinger]

There was some discussion in the bug report but I seems like we are going to integrate this change.

> On Jan 31, 2016, at 5:48 AM, Christian Thalinger <christian.thalinger at oracle.com> wrote:
> 
> Looks good.
> 
>> On Jan 29, 2016, at 4:34 PM, Doug Simon <doug.simon at oracle.com> wrote:
>> 
>> Please review this small change to further mitigate deadlocks that can be caused by JVMCI when BackgroundCompilation is disabled.
>> 
>> https://bugs.openjdk.java.net/browse/JDK-8148507
>> http://cr.openjdk.java.net/~dnsimon/8148507
>> 
>> -Doug
>