The previous patches are still not sufficient to build gdbserver with
our copy of thread_db.h.
../../../src/gdb/gdbserver/thread-db.c: In function ‘find_one_thread’:
../../../src/gdb/gdbserver/thread-db.c:316:6: error: ‘struct lwp_info’ has no member named ‘th’
../../../src/gdb/gdbserver/thread-db.c: In function ‘attach_thread’:
../../../src/gdb/gdbserver/thread-db.c:341:6: error: ‘struct lwp_info’ has no member named ‘th’
../../../src/gdb/gdbserver/thread-db.c: In function ‘thread_db_get_tls_address’:
../../../src/gdb/gdbserver/thread-db.c:514:47: error: ‘struct lwp_info’ has no member named ‘th’
make: *** [thread-db.o] Error 1
First, linux-low.h is including <thread_db.h> directly instead of our
gdb_thread_db.h, although thread-db.c includes the latter.  Then the
'th' field of struct lwp_info is only defined if HAVE_THREAD_DB_H is
defined, which is not true if we're using our replacement copy of
thread_db.h.  We have a USE_THREAD_DB symbol defined if we're building
thread-db.c that's ideal for this, however, it's currently only
defined when compiling linux-low.c (through a Makefile rule).  The
patch makes it defined when compiling any file.
gdb/gdbserver/
2013-04-16  Pedro Alves  <palves@redhat.com>
	* Makefile.in (INTERNAL_CFLAGS): Add @USE_THREAD_DB@.
	(linux-low.o): Delete rule.
	* linux-low.h: Always include "gdb_thread_db.h" instead of
	conditionally including thread_db.h.
	(struct lwp_info) <th>: Guard with #ifdef USE_THREAD_DB instead of
	HAVE_THREAD_DB_H.
+2013-04-16  Pedro Alves  <palves@redhat.com>
+
+       * Makefile.in (INTERNAL_CFLAGS): Add @USE_THREAD_DB@.
+       (linux-low.o): Delete rule.
+       * linux-low.h: Always include "gdb_thread_db.h" instead of
+       conditionally including thread_db.h.
+       (struct lwp_info) <th>: Guard with #ifdef USE_THREAD_DB instead of
+       HAVE_THREAD_DB_H.
+
 2013-04-07  Jan Kratochvil  <jan.kratochvil@redhat.com>
 
        * Makefile.in (install-only): Fix make install regression.
 
 INTERNAL_CFLAGS_BASE =  ${CFLAGS} ${GLOBAL_CFLAGS} \
        ${PROFILE_CFLAGS} ${INCLUDE_CFLAGS}
 INTERNAL_WARN_CFLAGS =  ${INTERNAL_CFLAGS_BASE} $(WARN_CFLAGS)
-INTERNAL_CFLAGS =  ${INTERNAL_WARN_CFLAGS} $(WERROR_CFLAGS) -DGDBSERVER
+INTERNAL_CFLAGS =  ${INTERNAL_WARN_CFLAGS} $(WERROR_CFLAGS) \
+       @USE_THREAD_DB@ -DGDBSERVER
 
 # LDFLAGS is specifically reserved for setting from the command line
 # when running make.
        $(POSTCOMPILE)
 
 i386_low_h = $(srcdir)/i386-low.h
-
-linux-low.o: linux-low.c
-       $(COMPILE) $< @USE_THREAD_DB@
-       $(POSTCOMPILE)
-
 win32_low_h = $(srcdir)/win32-low.h
 
 aarch64.c : $(srcdir)/../regformats/aarch64.dat $(regdat_sh)
 
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#ifdef HAVE_THREAD_DB_H
-#include <thread_db.h>
-#endif
+#include "gdb_thread_db.h"
 #include <signal.h>
 
 #include "gdbthread.h"
   int need_step_over;
 
   int thread_known;
-#ifdef HAVE_THREAD_DB_H
+#ifdef USE_THREAD_DB
   /* The thread handle, used for e.g. TLS access.  Only valid if
      THREAD_KNOWN is set.  */
   td_thrhandle_t th;