RFR: 8202976: Add C1 lea patching support for x86

[Per Liden]

Thanks Nils!

/Per

On 05/14/2018 01:51 PM, Nils Eliasson wrote:
> 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
>