Compiler passes:

- loading types from referenced assemblies (external/ directory)
- lexical analysis and parsing (parsing/ directory)
- build hierarchy of types existing in program (hierarchy/ directory)
- bind types in type hierarchy and add all class members to classes (hierarchy/TypeBuilder.n)
- perform typing of method's bodies (typing/ directory)
- transform translation of typed tree to intermediate representation 
  as compiled tree, which holds references directly to System.Reflection.Emit
  objects  (generation/ directory)
- output IL using System.Reflection.Emit.AssemblyBuilder from compiled tree (generation/ILGenerator.n)