9328cb896e
If libumfpack.so does not declare an explicit dependency on libamd.so, the linker option -Wl,--as-needed will cause an undefined reference since we don't use libamd.so ourself. If the configuration determines that this may be the case, a linker option that forces linking the the AMD library is added for the SuiteSparse library, and the general configuration then gets out of the way if this is set.