Enable sunlinsollapackdense even with no Fortran support. (#8923)

  - The only reason sundails wants to have Fortran support to enable
    `sunlinsollapackdense` is that it wants to figure out Fortran the name
    mangling scheme so that it can use the Lapack libraries needed.

    As it happens we can actually manually specify the name mangling scheme
    to avoid the requirement for a Fortran compiler.

    Thank you Sundials for being all around very well designed.