RFR(s): 8152188: Allow CMSBitMapYieldQuantum for BitMap::clear_range and clear_large_range

[sangheon]

Hi all,

Could I have a couple of reviews for this change?

CMSBitMapYieldQuantum can be changed by command-line and different 
values on this flag result in different ranges at BitMap when we clear 
the bitmap by BitMap::clear_large_range(). And if we can't satisfy the 
criteria for 'large' range of '32', we will face an assert from 
BitMap::clear_large_range().
As we already have clear_range(), it would be better to call it instead 
of firing an assert.
If we change to use 'clear_range()' will resolve the problem as well, 
but I didn't want to change like that which would result in performance 
regression.
In addition, we need a constraint to limit its maximum not to exceed the 
mark bitmap size.

CR: https://bugs.openjdk.java.net/browse/JDK-8152188
Webrev: http://cr.openjdk.java.net/~sangheki/8152188/webrev.00
Testing: JPRT, runtime/commandline JTREG tests for all platforms.

Thanks,
Sangheon