RFR: 8203344: Make C1 leal patchable on SPARC

[Erik Österlund]

Hi,

In C1, address resolution of an accessed field is not always possible, 
because the offset of the class of the object being accessed, has not 
yet been loaded. In ZGC, we use lea to resolve the address of fields. 
Therefore, the lea instruction needs to be patchable for ZGC. This 
enhancement aims to add support for such patching on SPARC.

Webrev:
http://cr.openjdk.java.net/~eosterlund/8203344/webrev.00/

Bug:
https://bugs.openjdk.java.net/browse/JDK-8203344

Thanks,
/Erik