Function boa::builtins::string::to_uppercase

pub fn to_uppercase(
    this: &Value, 
    _: &[Value], 
    ctx: &mut Interpreter
) -> ResultValue

Return a String with every code point mapped to its corresponding uppercase equivalent. With the current implementation the string is always copied even if the resulting String is identical https://tc39.es/ecma262/#sec-string.prototype.touppercase