Normalize main(..) routines for WinUWP

In order to support WinUWP platform, all main(..) routines must be normalized to the formal int main(int argc, char* argv[]) form. A platform wrapper main is auto-created linking against the default main(...). This can only work if the linkage is exactly matching the proper formal definition and not a loosely defined main(...) alternative.

Bug: webrtc:8608
Change-Id: I606663aaea7df1792c7c5636279617b8926fa5cc
Reviewed-on: https://webrtc-review.googlesource.com/28721
Reviewed-by: Patrik Höglund <phoglund@webrtc.org>
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21229}

modules/audio_coding/codecs/isac/main/test/SwitchingSampRate/SwitchingSampRate.cc

@@ -455,4 +455,5 @@ int main(int argc, char* argv[])
       //}
     }
   }
+  return 0;
 }

modules/audio_coding/neteq/tools/neteq_rtpplay.cc

@@ -677,5 +677,5 @@ int RunTest(int argc, char* argv[]) {
 }  // namespace webrtc
 
 int main(int argc, char* argv[]) {
-  webrtc::test::RunTest(argc, argv);
+  return webrtc::test::RunTest(argc, argv);
 }

modules/audio_coding/test/insert_packet_with_timing.cc

@@ -319,4 +319,5 @@ int main(int argc, char* argv[]) {
   test.TearDown();
   if (delay_log != NULL)
     fclose(delay_log);
+  return 0;
 }