[APFloat] Changed APFloat::isNormal => APFloat::isFiniteNonZero for all tests in unittests.

I forgot to to do this in r184356. The only references were in APFloatTest.cpp.
Debug Info: PR14763/r183329 - specify that non-trivial pass-by-value parameters are stored indirectly

This is to fix the location information for such parameters to refer to
the object accessible through the pointer rather than to the pointer
parameter itself.