Macro/Inline TODOs

[allanrenucci]

• Let macro authors inspect tree of the original arguments. One should not need to make these arguments by name
• Replace inline match with meta functionalities. Rewrite Tuple.scala (Implement tuple with quotes #5182)
• Drop inline optimisations
• Move inline after Pickling and before ReifyQuotes (Move inline β-reduction out of typer #5216)
• Move inline in ReifyQuotes and remove Inlined from TASTy (Move inlining into ReifyQuotes and remove Inlined from TASTy #5241)
• Simplify inline accessors (should fix Unexpected tree could not be interpreted #5097)
• Substitute by-name parameters directly without creating def bindings for them. (now is imposible as macros are expanded before bindings are inlined)
• Move dropUnused simplification after macro expansion. Move macro expnasion before dropUnused simplification

[nicolasstucki]

Inline should be after Typer. It should probably be before pickling or inspecting definitions that contain inline calls will not show the body with inlined calls. Hence we would have two different representation of the same tree depending of how it is accessed.

[nicolasstucki]

The alternative would be to retain trees at inlining time.

[nicolasstucki]

Actually the second might be a better solution