typing: AFor remove old `iterate` case

They where for old closures

Signed-off-by: Jean Privat <jean@pryen.org>
typing: AFor store services as CallSite (instead of MMethod)

Signed-off-by: Jean Privat <jean@pryen.org>
rta: use callsites in AFor instead re-resolving stuff

The code is so much simple now

Signed-off-by: Jean Privat <jean@pryen.org>
nit: use callsites in AFor instead re-resolving stuff

Signed-off-by: Jean Privat <jean@pryen.org>
typing: add `ARangeExpr::init_callsite` and use it everywhere

One more callsite, and less method got manually

Signed-off-by: Jean Privat <jean@pryen.org>
tests: update error messages

Signed-off-by: Jean Privat <jean@pryen.org>
Merge: CallSite on AFor and ARange

Use CallSite to resolve and type some implicit services.
Subsequent phases will like them!

Currenlty: all the AFor and ARange services are converted and tools updated.
TODO: Array and SuperString

Pull-Request: #370
Reviewed-by: Alexandre Terrasa <alexandre@moz-code.org>