Unusual or long compile time on solveGraphParametric!

[dehann]

building a 10 variable graph, and solving parametric takes 60s on first run, but then 0.2s on runs after that. @time reports 99.68% compile time for the first run. This is after a precompile of solveGraphParametric! on Pose3 using a smaller 2 variable graph.

TAC

Figure out why the compile times are so long even if a precompile on the variable and factor types has already been done.