Backout rev 1.10.

Requested by:	obrien

contrib/gcc/config/freebsd-spec.h

@@ -127,13 +127,49 @@ Boston, MA 02111-1307, USA.  */
   %{shared:crtendS.o%s} \
   crtn.o%s "
 
+/* Provide a LIB_SPEC appropriate for FreeBSD as configured and as
+   required by the user-land thread model.  Before __FreeBSD_version
+   500016, select the appropriate libc, depending on whether we're
+   doing profiling or need threads support.  At __FreeBSD_version
+   500016 and later, when threads support is requested include both
+   -lc and -lc_r instead of only -lc_r.  To make matters interesting,
+   we can't actually use __FreeBSD_version provided by <osreldate.h>
+   directly since it breaks cross-compiling.  As a final twist, make
+   it a hard error if -pthread is provided on the command line and gcc
+   was configured with --disable-threads (this will help avoid bug
+   reports from users complaining about threading when they
+   misconfigured the gcc bootstrap but are later consulting FreeBSD
+   manual pages that refer to the mythical -pthread option).  */
+
 /* Provide a LIB_SPEC appropriate for FreeBSD.  Just select the appropriate
-   libc, depending on whether we're doing profiling or not.
+   libc, depending on whether we're doing profiling or need threads support.
    (simular to the default, except no -lg, and no -p).  */
 
+#ifdef FBSD_NO_THREADS
 #define FBSD_LIB_SPEC "							\
-  %{pthread: %eThe -pthread option is deprecated.}			\
+  %{pthread: %eThe -pthread option is only supported on FreeBSD when gcc \
+is built with the --enable-threads configure-time option.}		\
   %{!shared:								\
     %{!pg: -lc}								\
     %{pg:  -lc_p}							\
   }"
+#else
+#include <sys/param.h>
+#if __FreeBSD_version >= 500016
+#define FBSD_LIB_SPEC "							\
+  %{!shared:								\
+    %{!pg: %{pthread:-lc_r} -lc}					\
+    %{pg:  %{pthread:-lc_r_p} -lc_p}					\
+  }"
+#else
+#define FBSD_LIB_SPEC "							\
+  %{!shared:								\
+    %{!pg:								\
+      %{!pthread:-lc}							\
+      %{pthread:-lc_r}}							\
+    %{pg:								\
+      %{!pthread:-lc_p}							\
+      %{pthread:-lc_r_p}}						\
+  }"
+#endif
+#endif