lower: Factor out common code for handling parameter, result and entity types in softfloat lowering.
lower: Factor out common code for handling parameter, result and entity types in softfloat lowering.

Checking 'is_Primitive_type()' achieves the same as 'mode && mode_is_float(mode)'.

libfirm/libfirm,libfirm/libfirm,MatzeB/libfirm,MatzeB/libfirm,libfirm/libfirm,MatzeB/libfirm,libfirm/libfirm,MatzeB/libfirm,libfirm/libfirm,MatzeB/libfirm,MatzeB/libfirm,MatzeB/libfirm