hijacks the analyzer to experiment with remembering original RefTrees
a minor clarification of a comment
HashMap[String, Any]-based metadata infrastructure for trees
remembers original idents from typedIdent with the new tree metadata infrastructure
more clarification
moves Metadata to foundation, so that noone has to use java.util.HashMap anymore
fixes an oversight in analyzer hijacking
undoes qualification of idents
oh man, the @converter macro is so capricious!
some simplification
better error messages for unexpected inputs/outputs during conversion
we would really make use of dotty's union types!
special treatment for self references, which are Idents converted to Thises
remembers original quals and names from typedSelect with the new tree metadata infrastructure
moves infix application detection to prelimResult postprocessing

this should simplify interaction with adaptation reversions that will soon be under implementation
hijacking of typed1 now only gets activated if we're not yet past typer
undoes qualifier transformations of selects

we still can't robustify detection of implicit conversions, because
those somehow come from a different place, other than typedSelectInternal
extends the previous commit to support adaptations to member
a todo for undoMacroExpansions
better error reporting for unreachable errors