TC-I, Function inlining

TC-I is an additional assignment.

At the end of this stage, the compiler inlines function bodies where functions are called. In a later pass, useless functions can be pruned from the AST. These features are triggered by the options --inline and --prune. If you also implemented function overloading (see TC-A, Ad Hoc Polymorphism (Function Overloading)), you can combine these extensions using --c-inline and --c-prune.