RFR: 8202976: Add C1 lea patching support for x86

[Nils Eliasson]

Looks good!

// Nils


On 2018-05-11 10:14, Per Liden wrote:
> This patch adds C1 support for patching lea instructions on x86. This 
> is used in ZGC load barrier stubs, when a load barrier is applied to a 
> field load with a not-yet-unknown offset.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8202976
> Webrev: http://cr.openjdk.java.net/~pliden/8202976/webrev.0
>
> Testing: passes hs-tier{1,2}, this patch has also been used and tested 
> in the ZGC repository for more than 3 years.
>
> /Per