Need a list of languages that are supported completely by ASCII encoding

IIRC from my Latin classes, the macrons in Latin are later additions by people studying meters in Latin poetry; they wouldn't have been used in every-day writing. So you've got Latin.

There are no natural languages that I know of that can be fully represented in ASCII. Even American English, the language for which ASCII was invented, doesn't work: for one, there are a lot of foreign words that have been integrated into the American English language that cannot be represented in ASCII, like resumé, naïve or a word that probably every programmer uses regularly, schönfinkeln.

And two, ASCII is missing pretty much all typographic characters like “quotation marks”, dashes of various lengths (– and —), ellipses (…), thin and wide spaces and so on, all of which are used in American English.