RFR(XS): 8214912: LogCompilation: Show the comp level

[Eric Caspole]

Hi everybody,
Could I have reviews on this small change to show the compilation level 
in the LogCompilation output similar to how it looks with 
+PrintCompilation, for example here the 3 is the level, after the id 606:

606 3      java.lang.Long::parseLong (267 bytes)


Webrev:
http://cr.openjdk.java.net/~ecaspole/JDK-8214912/webrev/

JBS:
https://bugs.openjdk.java.net/browse/JDK-8214912

Thanks,
Eric