REDIRECT_STDOUT_TO equivalent for stdin

Hi,
is there an equivalent way to `REDIRECT_STDOUT_TO `to capture the stdin?

I am trying to integrate JerryScript on the Portenta H7 [(my repository)](https://github.com/dmazzella/Arduino_Portenta_JerryScript).

Running scripts works fine, but to enable the "console" (repl) i need to use [fgetc](https://github.com/jerryscript-project/jerryscript/blob/0d4969661810b9e618485c284c361e597144e9b9/jerry-port/common/jerry-port-io.c#L64) required to enable [repl mode](https://github.com/jerryscript-project/jerryscript/blob/0d4969661810b9e618485c284c361e597144e9b9/jerry-ext/util/repl.c#L26)

Any suggestions?

Thank you,
D.

Start with REDIRECT_STDOUT_TO and the referenced jerry-port/common/jerry-port-io.c fgetc implementation, then read jerry-ext/util/repl.c to understand the stdin path needed for REPL mode. Determine whether ArduinoCore-mbed exposes an equivalent input-redirection mechanism for the Portenta H7; done means stdin can feed the JerryScript console.

Written by the indexing model from the issue text.