src: supply missing comments for CLI options

A few of the CLI option values exposed as properties on the process
object were missing a comment, fix this.

PR-URL: nodejs#12245
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>

src/node.cc

@@ -3317,6 +3317,7 @@ void SetupProcessObject(Environment* env,
     READONLY_PROPERTY(process, "_forceRepl", True(env->isolate()));
   }
 
+  // -r, --require
   if (preload_module_count) {
     CHECK(preload_modules);
     Local<Array> array = Array::New(env->isolate());
@@ -3339,10 +3340,12 @@ void SetupProcessObject(Environment* env,
     READONLY_PROPERTY(process, "noDeprecation", True(env->isolate()));
   }
 
+  // --no-warnings
   if (no_process_warnings) {
     READONLY_PROPERTY(process, "noProcessWarnings", True(env->isolate()));
   }
 
+  // --trace-warnings
   if (trace_warnings) {
     READONLY_PROPERTY(process, "traceProcessWarnings", True(env->isolate()));
   }