Serial.print causes ovf when printing doubles > 10 decimal digits (Due)

Serial.print causes ovf when printing doubles > 10 decimal digits (Due)
(AVR not tested but probably similar)

```

void setup() {
// put your setup code here, to run once:

Serial.begin(115200);
char str[30];

double f1=1234567.66;
double f2=12345678.66;
double f3=123456789.66;
double f4=1234567890.66;
double f5=12345678901.66;

Serial.println( f1 );
Serial.println( f2 );
Serial.println( f3 );
Serial.println( f4 );
Serial.println( f5 );
sprintf(str, "%.2f", f5 );
Serial.println(str);

}

void loop() {
// put your main code here, to run repeatedly:

}
```
output:

1234567.66
12345678.66
123456789.66
1234567890.66
ovf
12345678901.66

Reproduce the supplied sketch on an Arduino Due and compare the Serial.println outputs with sprintf(str, "%.2f", f5) and Serial.println(str). Start at the Serial.print/Serial.println handling for double values; done means the supplied values no longer produce "ovf" when printed directly and match the working formatted output.

Written by the indexing model from the issue text.