Move suppression of used-but-marked-unused warning to targets that aren't cellml.
Move suppression of used-but-marked-unused warning to targets that aren't cellml.

MichaelClerx/libcellml,MichaelClerx/libcellml,hsorby/libcellml,cellml/libcellml,nickerso/libcellml,MichaelClerx/libcellml,nickerso/libcellml,cellml/libcellml,cellml/libcellml,nickerso/libcellml,nickerso/libcellml,hsorby/libcellml,cellml/libcellml,hsorby/libcellml,hsorby/libcellml