RFR (XXS): 8008684 - CMS: concurrent phase start markers should always be printed

[Thomas Schatzl]

Hi all,

  this change always adds a timestamp marker for CMS concurrent phase
messages as suggested by the CR.
I added an extra space between timestamp and the original message for
better readability.

I.e. instead of printing

[CMS-concurrent-mark: 0.081/0.081 secs] [Times: user=0.16 sys=0.00,
real=0.09 secs] 
[CMS-concurrent-preclean: 0.005/0.005 secs] [Times: user=0.01 sys=0.00,
real=0.00 secs] 

the VM now prints 

20.014 [CMS-concurrent-mark: 0.081/0.081 secs] [Times: user=0.16
sys=0.00, real=0.09 secs] 
20.019 [CMS-concurrent-preclean: 0.005/0.005 secs] [Times: user=0.01
sys=0.00, real=0.00 secs] 

if -XX:+PrintGCDetails is set with CMS.

Webrev:
http://cr.openjdk.java.net/~tschatzl/8008684/webrev/

Bugs
http://bugs.sun.com/view_bug.do?bug_id=8008684

JIRA:
https://jbs.oracle.com/bugs/browse/JDK-8008684

Testing:
JPRT

Thanks,
  Thomas