When running llvm-lit driven tests allow extra parameters to be passed to solver.
When running llvm-lit driven tests allow extra parameters to be passed
to solver.

e.g.

$ llvm-lit --param=solver_params=--help .

kyledewey/stp,kyledewey/stp,kyledewey/stp,kyledewey/stp,kyledewey/stp,kyledewey/stp