8228420: compile error in shenandoahSupport.cpp with clang 9

[Aleksey Shipilev]

On 7/19/19 10:20 AM, Baesken, Matthias wrote:
> Bug/webrev :
> 
> https://bugs.openjdk.java.net/browse/JDK-8228420
> http://cr.openjdk.java.net/~mbaesken/webrevs/8228420/

Looks good and trivial. Please push!

-Aleksey