parser  parse source into ASTs, perform simple desugaring
         namer  resolve names, attach symbols to named trees
packageobjects  load package objects
         typer  the meat and potatoes: type the trees
superaccessors  add super accessors in traits and nested classes
       pickler  serialize symbol tables
     refchecks  reference and override checking, translate nested objects
      liftcode  reify trees
       uncurry  uncurry, translate function values to anonymous classes
     tailcalls  replace tail calls by jumps
    specialize  @specialized-driven class and method specialization
 explicitouter  C.this refs become outer pointers, translate pattern matches
       erasure  erase types, add interfaces for traits
      lazyvals  allocate bitmaps, translate lazy vals into lazified defs
    lambdalift  move nested functions to top level
  constructors  move field definitions into constructors
       flatten  eliminate inner classes
         mixin  mixin composition
       cleanup  platform-specific cleanups, generate reflective calls
         icode  generate portable intermediate code
       inliner  optimization: do inlining
      closelim  optimization: eliminate uncalled closures
           dce  optimization: eliminate dead code
           jvm  generate JVM bytecode
      terminal  The last phase in the compiler chain