RFR(s): ZGC: C2: Dont clone in self loop

[Nils Eliasson]

For reference:
compiler.c2.Test6877254 is a good reproducer for this problem.

// Nils

On 2018-05-29 13:11, Nils Eliasson wrote:
> Hi,
>
> Small fix for bug first reported by Aleksey.
>
> http://cr.openjdk.java.net/~neliasso/zgc/fix_clone_self/webrev/
>
> Please review,
>
> Regards
>
> Nils
>