Fail to build with Node.js ≥ 12

Hi,

when building with Node.js ≥ 12, I got some errors:

/usr/include/nodejs/deps/v8/include/v8.h:2588:31: note: candidate: ‘v8::Local<v8::String> v8::Value::ToString(v8::Isolate*) const’
 2588 |                 Local<String> ToString(Isolate* isolate) const);
      |                               ^~~~~~~~
/usr/include/nodejs/deps/v8/include/v8config.h:311:3: note: in definition of macro ‘V8_DEPRECATED’
  311 |   declarator __attribute__((deprecated(message)))
      |   ^~~~~~~~~~
/usr/include/nodejs/deps/v8/include/v8.h:2588:31: note:   candidate expects 1 argument, 0 provided
 2588 |                 Local<String> ToString(Isolate* isolate) const);
      |                               ^~~~~~~~
/usr/include/nodejs/deps/v8/include/v8config.h:311:3: note: in definition of macro ‘V8_DEPRECATED’
  311 |   declarator __attribute__((deprecated(message)))
      |   ^~~~~~~~~~
../src/node_zipfile.cpp:23:56: error: no matching function for call to ‘v8::Value::ToString()’
   23 | #define TOSTR(obj) (*String::Utf8Value((obj)->ToString()))

Inizia riproducendo la compilazione con Node.js ≥ 12 e ispeziona src/node_zipfile.cpp, in particolare la macro TOSTR alla riga 23. Confronta il suo utilizzo dell’API V8 con gli errori del compilatore, quindi verifica che il modulo nativo venga compilato correttamente con le versioni di Node.js interessate.