[11u] RFR: 8231586: enlarge encoding space for OopMapValue offsets

[Lindenmaier, Goetz]

Hi,

I had to resolve as the code indented after removal of two nested { 
differs.  Please review.

http://cr.openjdk.java.net/~goetz/wr20/8232083-Minimal_VM-after_8321586/01/
https://bugs.openjdk.java.net/browse/JDK-8232083
https://hg.openjdk.java.net/jdk/jdk/rev/3df2bf731a87

Best regards,
  Goetz.