RFR(S) 8233826 Change CDS dumping tty->print_cr() to unified logging

[Ioi Lam]

https://bugs.openjdk.java.net/browse/JDK-8233826
http://cr.openjdk.java.net/~iklam/jdk15/8233826-cds-change-tty-to-ul.v01/

During CDS dumping, a few messages are printed out unconditionally
using tty->print_cr(). This patch changes the message to use
log_info(cds) instead.

Some test cases were expecting the messages in stdout. I modified
these tests to explicitly pass -Xlog:cds.

Thanks
- Ioi