Only build libthread_db when both threads and debug are enabled

 -Erik

libpthread/Makefile

@@ -31,10 +31,10 @@ LIBTHREAD_DB_SHARED_FULLNAME=libthread_db-$(MAJOR_VERSION).$(MINOR_VERSION).$(SU
 DIRS=
 ifeq ($(strip $(INCLUDE_THREADS)),true)
 	DIRS+=linuxthreads
-endif
 ifeq ($(strip $(DODEBUG)),true)
 	DIRS+=linuxthreads_db
 endif
+endif
 
 ALL_SUBDIRS = linuxthreads linuxthreads_db