RFR: 8216385: ZGC: Fix building without C2

[Per Liden]

Thanks Aleksey!

/Per

On 01/08/2019 09:17 PM, Aleksey Shipilev wrote:
> On 1/8/19 9:14 PM, Per Liden wrote:
>> Building without C2 enabled (e.g. a client VM variant) fails after JDK-8215547, which introduced
>> unconditional uses of "MaxVectorSize", a symbol only available when C2 is enabled.
>>
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8216385
>> Webrev: http://cr.openjdk.java.net/~pliden/8216385/webrev.0
> 
> Looks fine and trivial.
> 
> -Aleksey
>