Art compiler: remove unnecessary sqrt call

For reasons lost in the mists of time, the Dalvik JIT tested
the results of an inlined sqrt for NaN on Arm targets, and then
called an out-of-line routine to recompute if true.  The Quick
compiler inherited this behavior.  It is not necessary, and the CL
purges it (along with the out-of-line sqrt entrypoint).

Change-Id: I8c8fa6feacf9b7c3b9e190dfc6f728932fd948c6