Move precompile.jl to the end

Author: YingboMa

src/ModelingToolkit.jl

@@ -152,8 +152,6 @@ using .SystemStructures
 include("systems/alias_elimination.jl")
 include("structural_transformation/StructuralTransformations.jl")
 
-include("precompile.jl")
-
 @reexport using .StructuralTransformations
 
 for S in subtypes(ModelingToolkit.AbstractSystem)
@@ -210,4 +208,6 @@ export modelingtoolkitize
 export @variables, @parameters
 export @named, @nonamespace, @namespace, extend, compose
 
+include("precompile.jl")
+
 end # module