[core] Fix some indirect inclusion issues (#2906).

* Removed unnecessary include of srt_compat.h from srt.h.
* Removed include of srt_compat.h and directly added it where it belongs.
* Added srt_compat.h include to srt-test-live.
* Added cstddef include to packet.cpp.

apps/srt-live-transmit.cpp

@@ -65,7 +65,7 @@
 #include <thread>
 #include <list>
 
-
+#include "srt_compat.h"
 #include "apputil.hpp"  // CreateAddr
 #include "uriparser.hpp"  // UriParser
 #include "socketoptions.hpp"

apps/srt-tunnel.cpp

@@ -27,6 +27,7 @@
 #include <mutex>
 #include <condition_variable>
 
+#include "srt_compat.h"
 #include "apputil.hpp"  // CreateAddr
 #include "uriparser.hpp"  // UriParser
 #include "socketoptions.hpp"

srtcore/common.cpp

@@ -68,8 +68,6 @@ modified by
 #include "packet.h"
 #include "threadname.h"
 
-#include <srt_compat.h> // SysStrError
-
 using namespace std;
 using namespace srt::sync;
 using namespace srt_logging;

srtcore/logging.cpp

@@ -14,7 +14,7 @@ written by
  *****************************************************************************/
 
 
-
+#include "srt_compat.h"
 #include "logging.h"
 
 using namespace std;

srtcore/logging.h

@@ -33,7 +33,6 @@ written by
 #include "utilities.h"
 #include "threadname.h"
 #include "logging_api.h"
-#include "srt_compat.h"
 #include "sync.h"
 
 #ifdef __GNUC__

srtcore/packet.cpp

@@ -159,7 +159,7 @@ modified by
 //      the original sequence numbers in the field.
 
 #include "platform_sys.h"
-
+#include <cstddef>
 #include <cstring>
 #include "packet.h"
 #include "handshake.h"

srtcore/srt.h

@@ -36,8 +36,6 @@ written by
 
 #include "platform_sys.h"
 
-#include "srt_compat.h"
-
 #include <string.h>
 #include <stdlib.h>
 

testing/srt-test-live.cpp

@@ -64,6 +64,7 @@
 #include <chrono>
 #include <thread>
 
+#include "srt_compat.h"
 #include "apputil.hpp"
 #include "uriparser.hpp"  // UriParser
 #include "socketoptions.hpp"