RFR: 8139765: set_numeric_flag can call Flag::find_flag to determine the flag type

[Dmitry Dmitriev]

Hello,

Please review enhancement of set_numeric_flag function in arguments.cpp 
module.
Current implementation of this function not determine the flag type and 
delegate this to the CommandLineFlags::<type>AtPut methods. If method 
succeed, then flag was processed. Otherwise try next type and so on. The 
bad thing that CommandLineFlags::<type>AtPut calls Flag::find_flag to 
find the flag and check his type. Thus, for size_t flag this operation 
will be repeated 6 times until appropriate CommandLineFlags::<type>AtPut 
found the flag.

In this enhancement I add CommandLineFlags::<type>AtPut which accepts 
'Flag*' argument. Other CommandLineFlags::<type>AtPut now calls method 
with 'Flag*' argument. In this case duplicated code was deleted for 
CommandLineFlags::<type>AtPut and CommandLineFlagsEx::<type>AtPut 
methods. New method for ccstrAtPut was not added because it not needed 
and CommandLineFlags and CommandLineFlagsEx have slightly different logic.

And finally set_numeric_flag function was modified to use 
CommandLineFlags::<type>AtPut with 'Flag*' argument. First of all 
set_numeric_flag looking for the flag by Flag::find_flag function. And 
then determine the flag type and call appropriate method. In this case 
we call Flag::find_flag function only once.

JBS: https://bugs.openjdk.java.net/browse/JDK-8139765
webrev.00: http://cr.openjdk.java.net/~ddmitriev/8139765/webrev.00/ 
<http://cr.openjdk.java.net/%7Eddmitriev/8139765/webrev.00/>
Testing: JPRT(hotspot test set), hotspot all, vm.quick

Thanks,
Dmitry