RFR (S) 8225342: Shenandoah: use COMPILER2_OR_JVMCI macro consistently

[Zhengyu Gu]

Looks good to me.

-Zhengyu

On 6/5/19 8:57 AM, Aleksey Shipilev wrote:
> RFE:
>    https://bugs.openjdk.java.net/browse/JDK-8225342
> 
> Webrev:
>    http://cr.openjdk.java.net/~shade/8225342/webrev.01/
> 
> This is cleaner and safer (in case COMPILER2 is actually globally defined but not available in
> current compilation unit).
> 
> Testing: hotspot_gc_shenandoah
>