Request for reviews (XXS): 7110058: change default for ScavengeRootsInCode to 2

[Christian Thalinger]

http://cr.openjdk.java.net/~twisti/7110058/

7110058: change default for ScavengeRootsInCode to 2
Reviewed-by:

The flag setting ScavengeRootsInCode=2 causes the JIT to inline more
constants.  This is generally a good thing for performance.

Tested with JPRT jobs on all three queues, DaCapo, refworkload
reference_server, JRuby test suite, Seph test suite.

src/share/vm/runtime/globals.hpp