review for 7103784: enable some flags by default

[Tom Rodriguez]

http://cr.openjdk.java.net/~never/7103784
3 lines changed: 0 ins; 0 del; 3 mod; 4396 unchg

7103784: enable some flags by default
Reviewed-by:

Enable UseCodeCacheFlushing, UseRDPCForConstantTableBase and
OptimizeStringConcat by default.  UseCodeCacheFlushing and
OptimizeStringConcat are tested by various settings in our nightlies
so there should only be minor issues.  UseRDPCForConstantTableBase has
been tested and was only off because the performance was unclear but
we believe it performs well on newer hardware.