RFR (S): 8135025: Error message is repeated for large value at G1ConcRefinementThreads

[sangheon.kim]

Hi all,

Can I get some reviews for handling thread creation failure on 
ConcurrentG1Refine?

This pre-existing problem is revealed during commandline test for GC 
flags(8078555) which tries to create for 'max_jint-1' threads.
The reason of repeating error message when thread creation failed is 
that we call 'vm_shutdown_during_initialization' when fails.
And this function just returns and then 'for loop' is continued for 
'max_jint-1'.

I separated thread initialization part from the constructor so that we 
can return when fails to create a new native thread.
And it will be handled from G1CollectedHeap::initialize().

I didn't add test because it is not stable.
 From windows 64, it takes really long time to fail a thread creation 
failure and hangs the system.
And 8134995(REDO: GC flag validation) will cover this situation.

CR: https://bugs.openjdk.java.net/browse/JDK-8135025
Webrev: cr.openjdk.java.net/~sangheki/8135025/webrev.00
Testing: JPRT

Thanks,
Sangheon