fix: fix @mtkbuild not working when @mtkcompile is not imported

Author: AayushSabharwal

src/deprecations.jl

@@ -5,7 +5,8 @@
 macro mtkbuild(exprs...)
     return quote
         Base.depwarn("`@mtkbuild` is deprecated. Use `@mtkcompile` instead.", :mtkbuild)
-        @mtkcompile $(exprs...)
+        $(Expr(:macrocall, var"@mtkcompile",
+            LineNumberNode(@__LINE__, @__FILE__), exprs...))
     end |> esc
 end
 

test/odesystem.jl

@@ -1614,3 +1614,10 @@ end
     @test_nowarn push!(arr, sys)
     @test_nowarn TestWrapper(sys)
 end
+
+module MtkbuildTestModule
+import ModelingToolkit: @variables, System, t_nounits as t, D_nounits as D, @mtkbuild
+@variables x(t)
+@mtkbuild sys = System(D(x) ~ t, t)
+@test sys isa System
+end