String::toInt() and atol() behave different on different platforms with a number that is too large.

User axemaster found strange behavior when using String::toInt() with a number that is too large. See the topic in the Arduino forum: [https://forum.arduino.cc/t/toint-bug-how-unfortunate/1041669](https://forum.arduino.cc/t/toint-bug-how-unfortunate/1041669).
The result is different for 8-bit and 32-bit platforms.
It was narrowed down to the undefined behaviour of atol() when a number is too large to fit in a long.

The atol() in String::toInt() in String.cpp could be replaced by strtol() followed by a check for LONG_MAX or LONG_MIN and return zero if that happens. The documentation can stay as it is, because it will return a long, and zero if something is wrong.
To allow LONG_MAX and LONG_MIN as valid input numbers, the errno has to be used. I don't know how that will hold up in a multitasking environment.

Inizia in String.cpp, su String::toInt(), e verifica come si comporta atol() per i valori al di fuori dell'intervallo long della piattaforma. Confronta il strtol() proposto e la gestione di errno sulle piattaforme 8-bit e 32-bit; l'issue è completata quando gli input troppo grandi producono risultati coerenti e documentati senza gestire erroneamente LONG_MAX o LONG_MIN.

Scritto dal modello di indicizzazione a partire dal testo della issue.