gcc: add some configuration and references.

-Add configure support for FreeBSD 10 and 11.
-Adapt a threading fix to gnu POSIX95 (which we don't use).
-Refer to a bug fix for the disabled vrptree support.

This is all useless in our current build but it is included
for convenience in case someone may want to re-package our
older gcc.

Reviewed by:	gerald (long ago)

contrib/gcc/config.gcc

@@ -428,6 +428,10 @@ case ${target} in
       tm_defines="${tm_defines} FBSD_MAJOR=8" ;;
     *-*-freebsd9 | *-*-freebsd[9].*)
       tm_defines="${tm_defines} FBSD_MAJOR=9" ;;
+    *-*-freebsd10 | *-*-freebsd[10].*)
+      tm_defines="${tm_defines} FBSD_MAJOR=10" ;;
+    *-*-freebsd11 | *-*-freebsd[11].*)
+      tm_defines="${tm_defines} FBSD_MAJOR=11" ;;
     *)
       echo 'Please update *-*-freebsd* in gcc/config.gcc'
       exit 1

contrib/gcc/gthr-posix95.h

@@ -115,9 +115,15 @@ __gthrw(pthread_setschedparam)
    it is passed so we cannot pretend that the interface is active if -pthreads
    is not specified.  On Solaris 2.5.1, the interface is not exposed at all so
    we need to play the usual game with weak symbols.  On Solaris 10 and up, a
-   working interface is always exposed.  */
+   working interface is always exposed. On FreeBSD 6 and later, libc also
+   exposes a dummy POSIX threads interface, similar to what Solaris 2.6 up
+   to 9 does.  FreeBSD >= 700014 even provides a pthread_cancel stub in libc,
+   which means the alternate __gthread_active_p below cannot be used there.  */
 
-#if defined(__sun) && defined(__svr4__)
+
+ */
+
+#if defined(__FreeBSD__) || defined(__sun) && defined(__svr4__)
 
 static volatile int __gthread_active = -1;
 
@@ -160,7 +166,7 @@ __gthread_active_p (void)
   return __gthread_active_latest_value != 0;
 }
 
-#else /* not Solaris */
+#else /* neither FreeBSD nor Solaris */
 
 static inline int
 __gthread_active_p (void)
@@ -170,7 +176,7 @@ __gthread_active_p (void)
   return __gthread_active_ptr != 0;
 }
 
-#endif /* Solaris */
+#endif /* FreeBSD or Solaris */
 
 #else /* not SUPPORTS_WEAK */
 

contrib/gcc/opts.c

@@ -504,7 +504,7 @@ decode_options (unsigned int argc, const char **argv)
       /* XXX: some issues with ports have been traced to -ftree-vrp.
          So remove it from -O2 and above.  Note that jdk1{5,6} are affected
          and they build with w/-O3 - so we cannot just move it to -O3. */
-      // flag_tree_vrp = 1;
+      /* flag_tree_vrp = 1; // See GCC tree-optimization/33099 */
 
       if (!optimize_size)
 	{