RFR(L): 8186027: C2: loop strip mining

[Roland Westrelin]

> UseCountedLoopSafepoints should be false by default too. Otherwise code in arguments.cpp will set LoopStripMiningIter to 
> 1. I will remove next change in c2_globals.hpp:
>
> -  product(bool, UseCountedLoopSafepoints, false,                            \
> +  product(bool, UseCountedLoopSafepoints, true,                             \

Right. Thanks for pushing this.

Roland.