RFR (S): 8234574: Rename prediction methods in G1Analytics

[Thomas Schatzl]

Hi all,

   could you review this change that renames the prediction methods of 
G1Analytics (and wrappers around them). This has been requested during 
an internal review of JDK-8227434.

This change has been split out to avoid re-reviewing later code already 
reviewed but not pushed yet due to missing dependencies and it's easier 
to review without functional changes mixed in.

Based on JDK-8233588.

CR:
https://bugs.openjdk.java.net/browse/JDK-8234574
Webrev:
http://cr.openjdk.java.net/~tschatzl/8234574/webrev/
Testing:
local compilation (this is a mechanical IDE supported rename of three 
methods)

Thanks,
   Thomas