os: assume UTF-8 for hostname

Do not assume Latin-1, but rather UTF-8 for the result of getting the
OS hostname.

While in 99 % of cases these strings are stored in ASCII, the OS does
not enforce an encoding on its own, and apparently the hostname is
sometimes set to non-ASCII data (despite at least some versions of
hostname(1) rejecting such input, making it even harder to write a
test for this which would already require root privileges).

In any case, these are short strings, so assuming UTF-8 comes
with no significant overhead.

Fixes: #27848

PR-URL: #27849
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Sam Roberts <vieuxtech@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>

src/node_os.cc

@@ -49,6 +49,7 @@ using v8::Integer;
 using v8::Isolate;
 using v8::Local;
 using v8::MaybeLocal;
+using v8::NewStringType;
 using v8::Null;
 using v8::Number;
 using v8::Object;
@@ -69,7 +70,9 @@ static void GetHostname(const FunctionCallbackInfo<Value>& args) {
     return args.GetReturnValue().SetUndefined();
   }
 
-  args.GetReturnValue().Set(OneByteString(env->isolate(), buf));
+  args.GetReturnValue().Set(
+      String::NewFromUtf8(env->isolate(), buf, NewStringType::kNormal)
+          .ToLocalChecked());
 }
 
 
@@ -84,7 +87,9 @@ static void GetOSType(const FunctionCallbackInfo<Value>& args) {
     return args.GetReturnValue().SetUndefined();
   }
 
-  args.GetReturnValue().Set(OneByteString(env->isolate(), info.sysname));
+  args.GetReturnValue().Set(
+      String::NewFromUtf8(env->isolate(), info.sysname, NewStringType::kNormal)
+          .ToLocalChecked());
 }
 
 
@@ -99,7 +104,9 @@ static void GetOSRelease(const FunctionCallbackInfo<Value>& args) {
     return args.GetReturnValue().SetUndefined();
   }
 
-  args.GetReturnValue().Set(OneByteString(env->isolate(), info.release));
+  args.GetReturnValue().Set(
+      String::NewFromUtf8(env->isolate(), info.release, NewStringType::kNormal)
+          .ToLocalChecked());
 }