clean up doxygen comments for main

src/main.cpp

 //===- subzero/src/main.cpp - Entry point for bitcode translation ---------===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
 /// \brief Defines the entry point for translating PNaCl bitcode into native
 /// code.
 ///
 //===----------------------------------------------------------------------===//
 
 #include "IceBrowserCompileServer.h"
 #include "IceBuildDefs.h"
 #include "IceCompileServer.h"
 
+/// Depending on whether we are building the compiler for the browser or
+/// standalone, we will end up creating a Ice::BrowserCompileServer or
+/// Ice::CLCompileServer object. Method
+/// Ice::CompileServer::runAndReturnErrorCode is used for the invocation.
+/// There are no real commandline arguments in the browser case. They are
+/// supplied via IPC so argc, and argv are not used in that case.
+/// We can only compile the Ice::BrowserCompileServer object with the PNaCl
+/// compiler toolchain, when building Subzero as a sandboxed translator.
 int main(int argc, char **argv) {
-  // Start file server and "wait" for compile request.
-  // Can only compile the BrowserCompileServer w/ the NaCl compiler.
   if (Ice::BuildDefs::browser()) {
-    // There are no real commandline arguments in the browser case. They are
-    // supplied via IPC.
     assert(argc == 1);
     return Ice::BrowserCompileServer().runAndReturnErrorCode();
   }
   return Ice::CLCompileServer(argc, argv).runAndReturnErrorCode();
 }