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

[Christian Thalinger]

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