Remove inclusion of source files.

From-SVN: r12218

gcc/objc/thr.c

@@ -113,20 +113,4 @@ objc_mutex_lock_x(_objc_mutex_t mutex, const char *f, int l)
     return objc_mutex_lock(mutex);
 }
 
-/*****************************************************************************
- *  Implementation specific functionality:
- */
-
-#if defined(__sparc__) && defined(__svr4__)     /* Solaris only code.       */
-#include "thr-solaris.c"
-#elif defined(__sgi__) && defined(__mips__)     /* IRIX only code.          */
-#include "thr-irix.c"
-#elif defined(__alpha__) && defined(__osf__)    /* Alpha OSF/1 only code.   */
-#include "thr-decosf1.c"
-#elif defined(__WIN32__)
-#include "thr-win32.c"
-#else						/* Single threaded code.    */
-#include "thr-single.c"
-#endif
-
 /* End of File */