Exemptions to taking IELTS/TOEFL/Regular GRE
If I were you, I'd write a letter to the admissions' departments at universities you're interested in to figure out what they'll want you to do.

I'm in a similar situation (graduated middle school, high school, and college in a non-English speaking country, but grew up in the United States until age 13), and I've already sent emails explaining my situation to universities that interest me. So far I've received a range of answers from I have to do TOEFL to I need to show evidence of living in America to they trust me and I don't need to show anything.

In regards to GRE's it differs from each university and country. In mathematics, you only need to do the GRE's (both regular and math subject), if you're planning to apply to the United States. If you don't want to do the GRE's, check out universities in Canada or Europe which don't require them.