Support printing unicode characters on windows

[andrjohns]

From #447, Unicode characters are not correctly printed to the console with console.log in some cases

[andrjohns]

@ahaoboy Can you try this branch to check that it works for you? All works as expected for me locally, but good to double-check

[ahaoboy]

Can you try this branch to check that it works for you?

Cool~ It works!

[chqrlie]

We might want to add an alternative function JS_ToWStringLen to convert a JS_STRING to a UTF-16 encoded wide string and use that for output. It would help if Microsoft would finally make it easy to use UTF-8 like the rest of the world.

[saghul]

@chqrlie Do you have any objections?

[bnoordhuis]

Wouldn't this work?

DWORD prev = GetConsoleOutputCP();
SetConsoleOutputCP(CP_UTF8);
WriteConsoleA(hConsole, str, len, &written, NULL);
SetConsoleOutputCP(prev);

Maybe you don't even need to use WriteConsoleA:

DWORD prev = GetConsoleOutputCP();
SetConsoleOutputCP(CP_UTF8);
fwrite(str, 1, len, con);
SetConsoleOutputCP(prev);